Health Conditions
547 conditions, each with the supplements studied for it and how strong the evidence is.
Condition list
- Best evidence:
Metabolic Health
Metabolic health describes how well your body turns food into energy, including how it handles blood sugar, insulin and fats. Among supplements, the evidence is strongest for beta-glucans, a fiber found in oats, where three studies of 538 people found blood glucose improved. MOTS-c, a mitochondrial peptide, also looked promising for insulin sensitivity, but mostly in mice, so what it means for people is unclear.
- Best evidence:
Type 2 Diabetes
Type 2 diabetes develops when the body resists insulin or makes too little, leaving blood sugar chronically high and slowly damaging blood vessels, nerves, kidneys, and eyes. Among supplements, beta-glucans and black seed oil have the strongest evidence: blood glucose improved with beta-glucans, and fasting glucose fell with black seed oil. Beta-glucan findings pooled only three studies, and the evidence for berberine, cinnamon, and magnesium was moderate, often from smaller trials.
- Best evidence:
General Athletic Performance
Athletic performance is the combined result of strength, power, endurance, speed, reaction time, and how well the body recovers. Creatine and caffeine have the strongest evidence, with thousands of people studied, and beta-alanine also improved anaerobic capacity in trials of high-intensity effort. Those beta-alanine gains were small and came from just two studies, while ashwagandha's aerobic gains rested on a single small study of 85 people.
- Best evidence:
High Cholesterol
High cholesterol means too much LDL, the so-called bad cholesterol, is circulating in the blood, made by the liver and absorbed from food, which raises the risk of heart disease and stroke. The evidence is strongest for black seed oil and bergamot, where reviews found LDL cholesterol fell, in some cases by a large amount. Studies varied in size, and reviews of oat beta-glucan mainly found better blood sugar.
- Best evidence:
Obesity
Obesity is a complex metabolic condition in which energy balance and hormones drift out of step, often alongside habits like emotional eating. Glucomannan and whey or casein protein have the strongest supplement evidence, and pooled trials of Triphala found lower body weight, BMI and waist size. Supplements sit alongside diet and exercise, the Triphala trials were small, and a saffron trial found less snacking in women, though that evidence is moderate.
- Best evidence:
Weight Loss & Maintenance
This goal refers to people with a BMI >25 attempting to reach/maintain their ideal weight. While interventions that work for people with a BMI >25 may also work for people with a lower BMI, the context is often sufficiently different that this isn't assured.
- Best evidence:
Immune Health
Your immune system is a network of white blood cells, antibodies, and signaling molecules that defend the body against germs, and it works less well when nutrients run short. Vitamin D and zinc have the strongest evidence behind them, while elderberry trials found colds lasted a shorter time and felt milder. That elderberry evidence is moderate and comes from small studies, and other compounds, like luteolin, have mostly been tested in lab work.
- Best evidence:
High Blood Pressure
High blood pressure is a long-term condition in which blood pushes too hard against artery walls, shaped by vessel width, blood volume, and how forcefully the heart pumps. Potassium and hibiscus have the strongest support: reviews found potassium lowered blood pressure, and hibiscus tea trials found readings improved in people with mildly raised pressure. The hibiscus trials were small, about 290 people in total, and the potassium evidence is moderate.
- Best evidence:
Metabolic Syndrome
Metabolic syndrome is a cluster of linked problems, including high blood pressure, high blood sugar, extra belly fat, high triglycerides and low HDL cholesterol, that reflects how the body handles sugar and fat. Berberine and omega-3 fatty acids have the strongest evidence among supplements, and large berberine trials found blood sugar improved. Vitamin D also improved blood sugar, but only in a few small studies, and the evidence for magnesium and chromium was limited.
- Best evidence:
Overweight
Being overweight means carrying more body fat than is ideal for your height, which raises the risk of type 2 diabetes and heart disease. The evidence is strongest for fiber and protein, which are thought to help people feel fuller, and in one small trial body fat went down with a probiotic. Still, that probiotic finding rests on one 12-week study of 92 people, so the evidence there is limited.
- Best evidence:
Muscle Size & Strength
Muscle grows when resistance training stresses the fibers and the body rebuilds them larger, using protein and rest. Creatine and protein have the strongest evidence: trials found creatine improved short, intense exercise capacity, and protein supplements, including soy, beef and casein, improved muscle mass, with gains similar to whey. Many of those studies were small, and supplements work alongside training rather than replacing it.
- Best evidence:
Aerobic Exercise Performance
Aerobic exercise performance is how well your body sustains endurance activity, which depends on delivering oxygen to muscles, using energy efficiently, and holding off fatigue. Among supplements, caffeine has the strongest evidence, and studies found aerobic measures improved, with moderate-sized effects; rhodiola and sodium bicarbonate showed similar gains. Rhodiola's evidence is moderate and sodium bicarbonate's studies were small, one involving only 22 people, so the results are best seen as early.
- Best evidence:
Cognitive Improvement
Cognitive improvement means sharpening normal brain function, including memory, attention and processing speed. Caffeine with L-theanine, as in tea, has the strongest evidence, and a review of trials found reaction time improved. That rests on one small study of 88 people, though, and evidence for other options, such as phosphatidylserine, is limited.
- Best evidence:
Body Composition
Body composition is the balance of lean mass, like muscle and bone, to fat in your body, which says more than scale weight does. Berberine and whey protein have the most to show: trials found BMI went down with berberine, and body fat went down with whey protein. The evidence is moderate for berberine but limited for whey, and the studies were small, often in older or postmenopausal women.
- Best evidence:
Dyslipidemia
Dyslipidemia means the blood fats are out of balance, with too much LDL cholesterol or triglycerides or too little HDL, which puts extra strain on the heart and blood vessels. Omega-3s, berberine and soluble fiber have the strongest overall evidence, and trials found apolipoprotein B, a marker of cholesterol-carrying particles, improved with berberine and with oat beta-glucan. The berberine studies were small, so the evidence for those markers is moderate rather than firm.
- Best evidence:
Cardiovascular Disease
Cardiovascular disease develops as fatty plaque slowly builds up in artery walls over decades, fueled by inflammation, oxidative stress and unhealthy blood fats. Among supplements, Panax notoginseng added to usual care eased angina symptoms in trial reviews, and curcumin improved blood sugar, with moderate evidence for each. Most angina trials came from China and varied in quality, and curcumin's effects were small.
- Best evidence:
Menopause
Menopause happens when the ovaries stop making estrogen and progesterone, usually around age 51, bringing hot flashes, night sweats, vaginal dryness, mood changes and poor sleep. The evidence is strongest for black cohosh and soy isoflavones, while red clover extract eased anxiety symptoms in one trial of 189 women. Most other findings come from single, small studies, and black cohosh showed no clear difference in one inflammation marker.
- Best evidence:
Nonalcoholic Fatty Liver Disease (NAFLD)
Nonalcoholic fatty liver disease is a buildup of fat in the liver without heavy drinking, often tied to insulin resistance and obesity, that can progress to inflammation and scarring. Berberine and vitamin E have the strongest supplement evidence, and in trials of tesamorelin, liver fat fell by more than a third. Those tesamorelin trials were in people with HIV, so the results may not apply more broadly.
- Best evidence:
Polycystic Ovary Syndrome (PCOS)
Polycystic ovary syndrome (PCOS) is a common hormonal condition marked by irregular periods, extra androgens and ovaries with many small follicles, often driven by insulin resistance, where high insulin nudges the ovaries to make more testosterone. Inositol and berberine have the most support, and trials found inositol lowered blood glucose while berberine improved a blood fat marker, apolipoprotein B. Still, the studies were small, and the evidence for those results is only moderate.
- Best evidence:
Muscle Recovery
Muscle recovery is the repair process after hard exercise, when tiny muscle tears and inflammation bring soreness and lost strength for a few days. Tart cherry and omega-3 fats have the strongest evidence, and a pooled analysis found curcumin lowered creatine kinase, a marker of muscle damage. That effect was small, and most other options rest on studies of only a few dozen people.
- Best evidence:
Coronary Artery Disease (CAD)
Coronary artery disease is a buildup of plaque in the heart's arteries that narrows them, reduces blood flow and raises heart attack risk. Omega-3s and coenzyme Q10 have the strongest standing, yet small trials found coenzyme Q10 raised antioxidant enzyme activity, and fish oil gave mixed results for atrial fibrillation after bypass surgery. Those studies were few and small, so the evidence behind them is limited.
- Best evidence:
Cycling Performance
Cycling performance is how well a rider can produce and sustain power, which depends on aerobic capacity, efficiency, and the ability to keep working hard through climbs and sprints. The evidence is strongest for caffeine and beetroot juice, and in trials caffeine improved aerobic measures of exercise by a moderate amount. Studies of beta-alanine and sodium bicarbonate were much smaller, so their benefits for hard efforts remain limited.
- Best evidence:
Mood Improvement
Mood is shaped by a balance of brain chemicals such as serotonin and dopamine, along with inflammation, the body's stress response and nutritional status. Saffron and vitamin D have the most support, and trials found anxiety symptoms improved with both, though the effects were small. The vitamin D trials were mostly in young girls with low levels and premenstrual mood troubles, and the saffron studies totaled only about 200 people, so the evidence is moderate at best.
- Best evidence:
Prediabetes
Prediabetes is when blood sugar runs higher than normal but not yet in the diabetes range, often because cells respond less well to insulin. Berberine, L-carnitine and saffron have the most support, and studies found blood glucose improved with each, with moderate evidence. Many of the studies were small, and some reviews also included people with type 2 diabetes, so results may not fit prediabetes alone.
- Best evidence:
Infertility
Infertility is difficulty conceiving that can stem from sperm, eggs, or both, and both depend on mitochondrial energy that fades with age and oxidative stress. Folic acid has the most support, with moderate evidence that sperm motility improved, while smaller trials found antioxidant enzymes went up in semen with coenzyme Q10 and DNA damage improved with L-carnitine. Those studies were small, and the findings mostly concern men rather than egg quality in women.
- Best evidence:
Stress
Stress is the body's response to demands or threats, and when it lingers, cortisol stays high and can bring fatigue, anxiety and poor sleep. Ashwagandha has the strongest evidence among the supplements looked at, and reviews of several trials found anxiety symptoms improved, with lemon balm and rhodiola showing similar gains. Much of this evidence is moderate, and the rhodiola trials were small, so the results are encouraging but not firm.
- Best evidence:
General Liver Health
The liver is the body's main filter, cleaning the blood, making bile for digestion, storing nutrients and neutralizing toxins. The evidence is strongest for milk thistle and N-acetylcysteine, and in trials artichoke extract improved liver enzymes. Those enzyme findings are still limited, and a tiny whey protein study of 11 women found mixed results on blood sugar, so bigger trials are needed.
- Best evidence:
Osteoarthritis (OA)
Osteoarthritis is a joint condition in which the cartilage cushioning your joints slowly breaks down, causing pain, stiffness and less mobility. Trials found systemic enzymes eased knee pain about as well as an anti-inflammatory drug, and chondroitin and glucosamine each improved pain, with moderate evidence. Still, the pain gains with chondroitin and glucosamine were small, so the differences were modest.
- Best evidence:
Running Performance
Running performance depends on aerobic capacity, how efficiently your muscles use oxygen, and how much of your top effort you can hold, plus recovery between sessions. The evidence is strongest for caffeine and beetroot juice, and trials found caffeine improved anaerobic capacity while nitrate improved measures of aerobic exercise. Those studies were small, some involving only a few dozen people or fewer, so the findings are encouraging rather than settled.
- Best evidence:
Chronic Kidney Disease (CKD)
Chronic kidney disease means the kidneys slowly lose their ability to filter waste and extra fluid from the blood, which raises heart risk. Coenzyme Q10 and black seed have moderate evidence, and small trials found blood glucose improved with the first and the inflammation marker CRP went down with the second. Those trials measured blood markers rather than kidney function itself, so the picture is still early.
- Best evidence:
Skin Health
Skin aging reflects a natural decline in collagen and elastin, plus damage from sunlight, pollution, and oxidative stress that brings wrinkles, sagging, and dryness. Collagen peptides have the most support, and a meta-analysis of randomized trials found skin elasticity improved. The evidence is moderate and the effect was small, while a 44-person trial found bakuchiol eased wrinkles about as well as retinol, so that result is early.
- Best evidence:
Bone Health
Bone health reflects a steady balance between osteoblasts, the cells that build bone, and osteoclasts, the cells that break it down, guided by minerals like calcium and by hormone signals. Among supplements, soy isoflavones and vitamin K have the most support, and meta-analyses of trials found bone mineral density improved with both, with moderate evidence. Vitamin D's evidence was limited, and strontium's strong fracture findings applied only to a prescription form.
- Best evidence:
Anaerobic Exercise Performance
Anaerobic exercise performance is how well you handle all-out efforts like sprints and heavy lifts, which run on oxygen-free energy systems that build up hydrogen ions and lactate, the source of the burn. Creatine and caffeine have the strongest support: jump height went up with creatine, and caffeine improved exercise measures across pooled reviews. Beta-alanine also improved anaerobic capacity, but that evidence is limited, drawn from small trials.
- Best evidence:
Depression
Depression is a mood condition tied to changes in brain chemistry, inflammation, and the brain's ability to form and adjust connections. Among supplements, St. John's wort and omega-3 fish oil have the strongest evidence, and trials found depression symptoms eased with both, to a moderate degree. The fish oil studies were small, and several focused on depression around pregnancy, while severe depression calls for professional care.
- Best evidence:
Cardiovascular Health
Cardiovascular health describes how well the heart and blood vessels move blood around the body, shaped by blood pressure and how flexible the arteries are. The clearest evidence involves blood pressure: a pooled analysis found aged garlic extract lowered systolic pressure by about 8 mmHg in people with hypertension, and trials found more sodium raised pressure, especially in salt-sensitive people. Bilberry and orange peel also showed moderate evidence, though those studies were small.
- Best evidence:
Human Immunodeficiency Virus (HIV)
HIV is a virus that attacks the immune system, especially CD4 T cells, though antiretroviral therapy has made it a manageable long-term condition. Research has looked mostly at multivitamin-multimineral formulas, where the evidence is strong, and selenium, where it is moderate, because deficiencies are common in HIV. In one small trial of people whose CD4 counts had responded poorly, adding bovine colostrum to therapy meant CD4 counts went up. Most other findings come from small studies.
- Best evidence:
Sleep Health
Sleep health describes how well you fall asleep, stay asleep and wake rested, which depends on your body clock and calming brain signals working together. Melatonin, the body's own sleep-timing hormone, is the supplement people look at most, and trials found insomnia symptoms improved. Those studies were small, though, with only 48 people across five of them, mostly older adults and children with insomnia, so the evidence is limited.
- Best evidence:
Mental Resilience
Mental resilience is the ability to adapt to stress and bounce back from adversity, supported by steady stress-hormone regulation, stable mood, and clear thinking under pressure. Ashwagandha, which is thought to calm the body's stress-hormone system, has the strongest evidence overall, and a small trial found rhodiola improved attention. That rhodiola result came from only 60 people, so the evidence for it is limited, and most other options have moderate evidence at best.
- Best evidence:
Type 1 Diabetes
Type 1 diabetes is an autoimmune condition in which the immune system destroys the pancreas cells that make insulin, so blood sugar climbs. For blood glucose, trials of saffron and magnesium found improvements, though the evidence is moderate for saffron and limited for magnesium. Studies were small, and some included people with type 2 diabetes, so insulin remains essential and these results are a rough guide.
- Best evidence:
Low Testosterone
Low testosterone, or hypogonadism, happens when the body makes too little of the main male sex hormone, which supports muscle, bone, energy, mood and libido. Vitamin D and zinc have the most support among supplements, with moderate evidence, and small trials in men with late-onset low testosterone found erections went up with tribulus. Most studies were small, though, and testosterone replacement remains the most effective option for true hypogonadism.
- Best evidence:
Age-Associated Memory Impairment and Cognitive Decline (AAMCD)
Age-related cognitive decline is the gradual slowing of mental abilities with age, like taking longer to learn things or losing a name, and it differs from dementia. Among supplements, the evidence is moderate for curcumin, where trials found cognition improved, and limited for ginkgo, which showed a similar result. Those studies were small, about 255 people for curcumin and 59 for ginkgo, so the picture is still early.
- Best evidence:
Antioxidant Status
Antioxidant status describes how well your body's defenses, such as superoxide dismutase and glutathione, keep reactive molecules called free radicals in check. The evidence is strongest for copper and manganese, where SOD activity went up, and limited for piperine, where trials pairing it with curcumin or turmeric found oxidative stress markers improved. Most other supplements rest on small trials, and some mostly on animal or lab work.
- Best evidence:
Schizophrenia
Schizophrenia is a serious mental illness in which brain signaling, including glutamate activity at NMDA receptors, is thought to go awry, shaping thoughts, motivation and emotion. Among supplements, the evidence is strongest for sarcosine, with moderate evidence for glycine and D-serine. Trials found overall symptoms improved with sarcosine and glycine, and cognition improved with D-serine. Still, these studies were small, the sarcosine finding rests on one trial, and people used them alongside usual antipsychotic medication.
- Best evidence:
Alzheimer’s Disease
Alzheimer's disease is a progressive brain disorder in which amyloid plaques and tau tangles build up, inflammation persists, and neurons, especially those using acetylcholine, are gradually lost, causing memory loss and confusion. Among supplements, the alpha-GPC trial found symptoms improved in mild to moderate Alzheimer's, and saffron trials found similar gains. Evidence is limited for alpha-GPC and moderate for saffron, and both studies were small.
- Best evidence:
Male Sexual Dysfunction
Erectile dysfunction is trouble getting or keeping an erection, often because blood flow to the penis is reduced. Korean red ginseng has the best support, with trials finding that erections went up and the evidence rated moderate; yohimbine and saffron also showed improvements, though that evidence is limited. Those studies were small, with about 200 people across the ginseng trials, so the results are preliminary.
- Best evidence:
Pregnancy and Delivery Health
Pregnancy sharply raises the body's need for nutrients, because a growing baby draws on them to form its organs. Vitamin D and iron have the most support: a meta-analysis found pre-eclampsia became less common with vitamin D, and iron raised ferritin, a measure of the body's iron stores. Ferritin is only a marker, though, and folic acid's effect on birth weight was mixed.
- Best evidence:
Rheumatoid Arthritis (RA)
Rheumatoid arthritis is a long-term condition in which the immune system mistakenly attacks the joint lining, causing inflammation, pain and gradual cartilage damage. Among supplements, trials found rheumatoid factor reduced with andrographis, arthritis symptoms improved with krill oil, and C-reactive protein, an inflammation marker, went down with boron. Most of these studies were small, with under 100 people, so the evidence is mostly limited.
- Best evidence:
Healthy Muscle Aging
Sarcopenia is the gradual loss of muscle mass and strength with age, which raises the risk of weakness, falls and frailty as muscles respond less to protein and activity. Creatine, protein and vitamin D have the strongest evidence behind them, and trials of whey in older women found body fat went down. That whey evidence was limited, from two small studies, and the remaining supplements have moderate support at best.
- Best evidence:
Premenstrual Syndrome (PMS)
Premenstrual syndrome is a cluster of mood and physical symptoms, such as bloating and breast tenderness, that shows up after ovulation, linked to hormonal shifts that affect brain chemistry. The evidence is strongest for lemon balm and chaste tree: trials found PMS symptoms eased with lemon balm, and breast tenderness eased with chaste tree. Only two lemon balm trials, in teenage girls, and one chaste tree trial were reviewed, so the results are early.
- Best evidence:
Heart Failure
Heart failure means the heart cannot pump blood well enough for the body's needs, and the energy-starved muscle struggles to contract, leaving people tired, breathless and prone to fluid buildup. Coenzyme Q10 and omega-3 fatty acids have the strongest support among supplements, and small trials of coenzyme Q10 found blood flow went up. Those trials included only 23 people in total, so the evidence for that finding is limited.
- Best evidence:
Hormone Health
Hormones are chemical messengers from glands like the thyroid, adrenals and ovaries that steer metabolism, growth, mood, sleep and stress response. The evidence is strongest for vitamin D, studied in about 20,000 people, with moderate evidence for ashwagandha, which was looked at for stress and thyroid hormones. Most other findings came from small studies, and several, including flaxseed and calcium, found no clear difference in hormone levels.
- Best evidence:
Nonalcoholic Steatohepatitis (NASH)
NASH is a serious form of fatty liver disease in which fat buildup sparks inflammation and liver cell damage, driven by metabolic problems like insulin resistance rather than alcohol. Silymarin from milk thistle has the most reviewed research, and six studies found liver enzymes improved, with moderate evidence. Betaine showed a similar improvement, though that research was small, involving only 30 people.
- Best evidence:
Anxiety Disorders (Other)
Anxiety disorders involve an overactive stress response, with the brain's alarm centers running hot while calming GABA signals weaken, feeding a cycle of worry, tension and a racing heart. Kava has the strongest evidence, and reviews found anxiety symptoms improved, with ashwagandha and lavender close behind at a moderate level. Much of the lavender work came from dental-office settings, and the saffron studies were small, so the picture is still uneven.
- Best evidence:
Asthma
Asthma is a long-term condition in which the airways become inflamed and overly sensitive, so they narrow easily and cause wheezing, chest tightness, breathlessness and coughing. Probiotics, magnesium and saffron have the most support, and small trials found asthma symptoms improved with each, with moderate evidence. Those studies were small, often in children, and they were mostly add-ons to usual asthma care.
- Best evidence:
Chronic Obstructive Pulmonary Disease (COPD)
COPD is a progressive lung disease in which long-lasting inflammation, narrowed airways, and damage to lung tissue make breathing harder, with oxidative stress and repeated infections playing big roles. The evidence is strongest for N-acetylcysteine, and a pooled analysis of trials found bronchitis symptoms improved in people with chronic bronchitis. The effect was small, though, and omega-3 fatty acids showed no clear difference in walking test performance, so the wider picture is still limited.
- Best evidence:
Fatigue
Fatigue is a lingering lack of energy, often tied to poor sleep, stress, low iron or B12, or thyroid problems. The evidence is strongest for iron and moderate for rhodiola: a trial in women with low iron stores found anxiety symptoms improved, and rhodiola studies found better attention. Those studies were small, and the iron results mostly apply to women with low stores.
- Best evidence:
Digestive Health
Digestive health reflects how well your gut breaks down food, absorbs nutrients and signals your brain, with troubles like bloating, constipation or reflux. The evidence is strongest for senna and psyllium fiber, and trials of senna found intestinal motility went up. Those studies were small, though, with 165 people for senna, and its trials centered on constipation after childbirth or surgery.
- Best evidence:
General Cancer Care and Prevention
Cancer is a group of diseases in which cells ignore signals to stop dividing or die, multiplying unchecked and sometimes spreading. Vitamin D and omega-3 fatty acids carry the strongest evidence, rated moderate, and smaller studies found lower colorectal cancer risk with Korean ginseng and better immune measures with reishi. The ginseng and reishi findings are limited, and vitamin E and beta-carotene showed no clear benefit.
- Best evidence:
Migraine Headache
A migraine is a recurring, often one-sided headache that can bring nausea and sensitivity to light and sound, driven by abnormal brain activity, blood-vessel changes and inflammation. Among supplements, the evidence is moderate for butterbur, where attacks fell by 48% versus 26% on placebo, and for vitamin D, where migraine frequency went down, though a riboflavin trial found no clear difference. Vitamin D's study was small, so these findings are tentative.
- Best evidence:
Atherosclerosis
Atherosclerosis is a slow buildup of fatty plaque in artery walls, driven by cholesterol-carrying particles and inflammation, which narrows and stiffens the vessels. Berberine has the most research behind it, and small studies found lower C-reactive protein, a marker of inflammation; apolipoprotein A went up with niacin, and HDL cholesterol improved with L-carnitine. Still, the evidence is mostly limited, built on small trials, and naringenin's promise came largely from animal work.
- Best evidence:
Fibromyalgia
Fibromyalgia is a long-term condition of widespread pain, fatigue, and foggy thinking, in which the nervous system seems to amplify pain signals. The evidence is moderate for coenzyme Q10, where a trial found pain and fatigue eased, and limited for D-ribose, where fatigue improved. Those D-ribose results came from only 36 people, so they are early findings, not settled ones.
- Best evidence:
Upper Respiratory Tract Infection
An upper respiratory tract infection is a usually viral illness of the nose, throat, or sinuses, such as the common cold, in which the body's immune response causes congestion, sore throat, and cough. Among supplements, beta-glucans have the clearest support: a review found people had fewer infections, and the evidence is moderate. Echinacea eased cold symptoms in small studies, but the evidence is limited, and vitamin C and zinc showed no clear difference in the few trials reviewed here.
- Best evidence:
Soccer Performance
Soccer performance draws on endurance, repeated sprints, agility, technical skill and clear thinking, often across crowded match schedules. Creatine and caffeine have the strongest evidence for supporting sprint power and stamina, and in one small study of players, N-acetylcysteine improved anaerobic capacity. Soccer-specific trials were mostly small, often a dozen to a few dozen players, so the evidence for most individual supplements is limited.
- Best evidence:
Stroke
A stroke happens when a blocked or burst blood vessel cuts off blood flow to part of the brain, starving cells of oxygen. Among supplements, B vitamins and zinc have the best-supported results: stroke risk was slightly lower with B vitamins in longer trials in places without folate-fortified food, and thinking skills improved with zinc in a small trial. The evidence is limited, though, and the zinc result came from just 26 people.
- Best evidence:
Sexual Health
Sexual health relies on hormones, blood flow, nerves, and mood working together, so stress, aging, or conditions like diabetes can dampen desire and erections. The evidence is moderate for Tongkat Ali, where research found erections went up. That finding came from one small study of 128 people, and tribulus showed no clear difference in a hormone measure among just 21 people.
- Best evidence:
Breast Cancer
Breast cancer is a disease in which breast cells grow out of control, often fueled by hormones such as estrogen. Among supplements, vitamin D has drawn the most attention, and in one small trial of women starting aromatase-inhibitor treatment, joint pain improved. That study included only 60 women, so the evidence is limited and needs larger trials to confirm it.
- Best evidence:
Mild Cognitive Impairment (MCI)
Mild cognitive impairment is the stage between normal age-related changes and dementia, when memory or thinking problems are noticeable but don't yet disrupt daily life. Among supplements, folic acid has moderate evidence, with a meta-analysis of trials finding better cognition, and B vitamins improved memory and slowed brain shrinkage in people with high homocysteine. Those studies were small, and the B vitamin benefits appeared mainly in people with high homocysteine.
- Best evidence:
Surgical Recovery
Surgical recovery is the period after an operation when the body repairs tissue, guards against infection, and regains normal function. Ginger has the strongest evidence, with nine small trials finding that nausea after surgery improved, and inflammation went down with serrapeptase after wisdom tooth surgery. Still, the studies were small and the enzyme evidence is only moderate, so results may not apply to every operation.
- Best evidence:
End-Stage Renal Disease
End-stage renal disease is when the kidneys have lost nearly all function, letting toxins, fluid, and minerals build up in the blood and making dialysis or a transplant necessary. Among supplements, L-carnitine and cordyceps have the most support, with moderate evidence: trials found blood pressure improved with L-carnitine, and blood urea nitrogen went down with cordyceps. Those studies were small, and several other supplements showed no clear difference in inflammation.
- Best evidence:
Infant Health
Infancy is a time of very fast growth, when the brain, bones and immune system are being built, and breast milk or formula supplies most but not all of the nutrients needed. The evidence is strongest for vitamin A, vitamin D and iron, and in large vitamin A studies, diarrhea symptoms improved. Iron research came partly from pregnancy, where one review found birth weight changed without a clear direction, and many other findings are small or limited.
- Best evidence:
Osteoporosis
Osteoporosis is a condition in which bone breakdown outpaces bone building, leaving bones porous and fragile, a shift that speeds up after menopause as estrogen falls. Among supplements, vitamin K and vitamin D have the most support, and trials found bone mineral density improved with each, with the evidence moderate for both. The vitamin D findings came from only two studies and the gain was small, and these trials looked at bone density rather than fractures.
- Best evidence:
Rowing Performance
Rowing performance is how much power a rower can sustain over a race, which depends on energy supply, oxygen delivery, and buffering the acid that builds up in muscle. Sodium bicarbonate has the most support, and studies found anaerobic capacity improved, while blood lactate went down during exercise with rhodiola. Still, the evidence is limited: effects were small, the studies tiny, and some bicarbonate work involved swimmers.
- Best evidence:
Allergic Rhinitis (Seasonal Allergies / Hay Fever)
Allergic rhinitis, or hay fever, is an immune overreaction to harmless things like pollen, in which mast cells release histamine and cause sneezing, a runny nose, congestion and itchy eyes. Butterbur and spirulina have the most support, with moderate evidence: trials found butterbur eased symptoms about as well as cetirizine without sedation, and symptoms improved with spirulina. Spirulina's findings rest on only two studies of 194 people.
- Best evidence:
Erectile Dysfunction
Erectile dysfunction is trouble getting or keeping an erection firm enough for sex, usually a blood-flow problem that depends on nitric oxide relaxing blood vessels. The evidence is strongest for Korean red ginseng, with moderate support for L-citrulline and L-carnitine, and in two small carnitine trials, erections went up. Those trials included only 147 men and paired carnitine with other treatments, so the findings are early.
- Best evidence:
Insomnia
Insomnia is trouble falling or staying asleep, often linked to stress, irregular schedules, or age-related shifts in sleep hormones that disrupt the body's natural sleep-wake cycle. Melatonin has the strongest evidence, and across five studies people with insomnia saw their symptoms improve, including older adults and children. Magnesium looked much less convincing, with no clear difference in insomnia symptoms in a very small group, so most other options rest on limited, small studies.
- Best evidence:
Focus & Attention
Focus is the brain's ability to stay on one task while filtering out distractions, shaped by sleep, stress, nutrition and signaling between brain cells. The evidence is strongest for caffeine paired with L-theanine, linked to calmer alertness and sharper focus, and a small trial found attention improved with Korean ginseng. That ginseng trial involved only 32 people, and Bacopa showed no clear difference in attention, so the wider picture is still early.
- Best evidence:
Peripheral Arterial Disease
Peripheral arterial disease happens when narrowed arteries, usually from atherosclerosis, reduce blood flow to the legs, often causing cramping pain when walking. The evidence is strongest for L-carnitine, though trials mostly showed blood carnitine levels went up, and blood flow went up with cocoa extract in limited research. The cocoa studies involved few people, and omega-3 showed no clear difference in blood flow.
- Best evidence:
General Gut Health
Gut health describes how well your digestive tract and its trillions of microbes work together to digest food, support immunity, and keep a barrier against harmful substances. The evidence is strongest for resistant starch, which raised fecal short-chain fatty acids in trials, and for psyllium, which changed stool weight. Those studies were small, with 136 and 32 people, and which way psyllium moved stool weight was unclear.
- Best evidence:
Endometriosis
Endometriosis is a chronic condition in which tissue like the uterine lining grows outside the uterus, causing inflammation, scarring, and pelvic pain. The strongest evidence is for the hormone-lowering medicines leuprolide and nafarelin: trials found leuprolide eased pelvic pain better than placebo, and most people on nafarelin had less visible endometriosis on laparoscopy. Evidence for nutrients such as omega-3s and vitamin D is only moderate.
- Best evidence:
Memory Improvement
Memory is how the brain encodes, stores and retrieves information, using different regions and chemical messengers for working, short-term and long-term recall, and it naturally slips with age. Among supplements, Bacopa has the best-supported case, and trials found memory improved, with iron also linked to better measures of intelligence, though the evidence is moderate for both. Studies were mostly small, and ginkgo and phosphatidylserine showed only limited gains in cognition, while choline and a herbal extract called Polygala showed no clear difference.
- Best evidence:
Eye Health
Eye health depends on the retina, lens and other delicate tissues staying clear and working well, and macular degeneration and cataracts involve gradual age-related wear on them. Lutein and zeaxanthin have the strongest evidence, with omega-3s moderate, and a study of 91 people found a gramicidin-containing eye drop effective for bacterial corneal ulcers. That ulcer study looked back at past cases, and bilberry's easing of screen-related focusing strain came from just 141 people.
- Best evidence:
Common Cold
The common cold is a viral infection of the nose and throat, most often caused by rhinoviruses, where the immune response brings inflammation that causes a runny nose, congestion, sore throat and cough. Zinc and elderberry have the best support, and trials found cold symptoms improved with both, though the effects were small. Elderberry's results came from just three small studies, and vitamin C showed no clear difference in how often people caught colds.
- Best evidence:
Diabetic Nephropathy
Diabetic nephropathy is kidney damage from long-term diabetes, in which high blood sugar injures the tiny filtering units of the kidneys, letting protein leak into urine and slowly dulling kidney function. Curcumin and saffron are among the supplements studied, and small trials found blood pressure improved with each. The evidence is limited, though: the trials were small, with 40 and 80 people, and some involved other groups rather than people with kidney disease.
- Best evidence:
Prostate Cancer
Prostate cancer develops when cells in the prostate gain mutations, evade the immune system, and rewire their metabolism. Hormone-lowering medicines have the strongest research, and trials found degarelix and triptorelin brought testosterone to very low levels in nearly all men, with degarelix doing so within days. Supplement evidence is thinner: flavonoids reached only moderate support, and vitamin E showed no clear difference in cancer deaths.
- Best evidence:
Warm- or Hot-Weather Exercise Performance
Exercising in the heat forces your body to work harder to cool itself while also powering the workout, which can blunt performance and, in severe cases, lead to heat illness. The evidence is strongest for electrolytes and carbohydrates, which replace minerals lost in sweat and fuel long efforts. Small trials of quercetin, betaine and tyrosine, with 10 to 31 people, found no clear difference in performance measures.
- Best evidence:
Irritable Bowel Syndrome (IBS)
Irritable bowel syndrome is a gut condition in which the brain-gut connection is disrupted, leaving the intestines oversensitive so normal signals bring pain, bloating, and changed bowel habits. Evidence is strongest for peppermint oil, where trials found symptoms improved, and probiotics, with moderate evidence, also eased abdominal pain. The peppermint effect was moderate in size across seven trials of 392 people, while prebiotics and synbiotics showed no clear difference in pain.
- Best evidence:
Multiple Sclerosis (MS)
Multiple sclerosis is an autoimmune condition in which the immune system attacks myelin, the protective coating on nerve fibers in the brain and spinal cord, disrupting signals and causing fatigue, weakness and numbness. Among supplements, vitamin D and omega-3 fatty acids have the strongest evidence, rated moderate, while trials of high-dose biotin in progressive MS found no clear difference in symptoms. Most other studies were small, so the evidence is limited overall.
- Best evidence:
Swimming Performance
Swimming performance is how fast and how long a swimmer can go, drawing on stored phosphocreatine for sprints, anaerobic capacity for middle distances, and aerobic endurance for longer events. Caffeine has the strongest evidence and creatine comes next, but the swimming results available cover beta-alanine, where two small studies found anaerobic capacity improved. Those studies included just 41 people, so the evidence is limited, and creatine showed no clear aerobic difference.
- Best evidence:
Gestational Diabetes
Gestational diabetes is diabetes that first appears in pregnancy, when hormones make the body resistant to insulin and some women can't make enough extra to keep blood sugar steady. Inositol has the strongest backing among supplements, and trials found it raised adiponectin, a hormone linked to insulin sensitivity, while high-fibre diets improved blood sugar with moderate evidence. Most studies were small, and chromium and zinc showed only limited hints of better blood sugar.
- Best evidence:
Dementia
Dementia is a decline in memory and thinking that comes from damaged nerve cells, weaker chemical signaling between them, and reduced blood flow to brain tissue. Among supplements, oxiracetam has the strongest evidence, and small trials found thinking and memory decline improved, with limited evidence that alpha-GPC eased Alzheimer's symptoms. Most studies were small, and ginkgo biloba showed no clear difference in Alzheimer's risk in a large trial.
- Best evidence:
Female Sexual Dysfunction
Female sexual dysfunction means ongoing trouble with desire, arousal, orgasm, or pain during sex, often driven by hormonal shifts, stress, antidepressants, or medical conditions. Tribulus has moderate evidence behind it, with small trials finding libido went up, and early bremelanotide studies found better subjective arousal. Most of this work was small, though, and one DHEA study found no clear difference in libido.
- Best evidence:
Kidney Health
Kidney health describes how well your kidneys filter waste, balance fluids, and keep blood pressure and minerals in check, work that chronic kidney disease can quietly wear down. Among supplements, omega-3s, resveratrol, and sodium bicarbonate have moderate evidence, and in resveratrol studies blood urea nitrogen went down, while a review of intravenous glutamine found no clear difference in deaths. Those resveratrol effects were small, and evidence for the rest is thinner.
- Best evidence:
Martial Arts Performance
Martial arts performance is the blend of explosive power, muscular endurance, quick reactions and fast recovery that strikes, throws and grappling demand. The evidence is strongest for creatine and caffeine, which people use for power output and reaction time. Direct findings are thin, though: one tiny study of 10 people found better blood glucose with creatine, and two small studies found lower blood lactate with sodium bicarbonate.
- Best evidence:
Primary Dysmenorrhea (Menstrual Cramps)
Primary dysmenorrhea is painful menstrual cramping with no underlying pelvic condition, caused by prostaglandins, inflammatory chemicals released from the uterine lining that make the uterus contract. Among supplements, vitamin E has the most support, with moderate evidence, and symptoms eased in small trials; a ginger trial also found less pain. Still, the studies were small and ginger rests on one trial.
- Best evidence:
Bipolar Disorder
Bipolar disorder is a mood condition in which a person swings between depressive episodes and episodes of mania or milder hypomania, involving changes in brain circuits that regulate mood and energy. Among supplements, the evidence is strongest for fish oil rich in EPA, and five small trials found bipolar symptoms improved. Those trials included only about 260 people, and studies of inositol and CDP-choline found no clear difference, though each was very small.
- Best evidence:
Iron Deficiency Anemia
Iron deficiency anemia occurs when the body does not have enough iron to produce healthy red blood cells to transport oxygen in the blood. Iron deficiency anemia can be caused by excessive blood loss or reduced iron absorption or intake. It can be treated with oral iron supplementation, though there is a wide range of individual tolerance for, and effectiveness of, iron supplements.
- Best evidence:
Neurological Health
Neurological health is about keeping the brain and nervous system working well; the brain uses about 20% of the body's energy, which leaves it vulnerable to oxidative stress and inflammation. Omega-3s, vitamin D and B vitamins have the strongest evidence overall, and after traumatic brain injury, Cerebrolysin trials found improved recovery scores. Much of the brain-protection research, such as on humanin, comes from lab work, and BPC-157 findings are mostly from animals.
- Best evidence:
Generalized Anxiety Disorder (GAD)
Generalized anxiety disorder is a condition of persistent, hard-to-control worry about many parts of life, often with muscle tension, restlessness and poor sleep, driven by an overactive stress response in the brain. Passionflower has the strongest evidence, and trials found anxiety symptoms eased, as they did in smaller bodies of research on saffron and ashwagandha. Still, the studies were small, so the evidence is moderate for passionflower and limited for the others.
- Best evidence:
Chronic Venous Insufficiency
Chronic venous insufficiency happens when damaged valves in the leg veins let blood pool instead of flowing back to the heart, leading to heaviness, aching, swelling and sometimes skin changes. Among supplements, gotu kola, horse chestnut and diosmin have the strongest evidence, and studies found signs of the condition improved with the first two, while a large review found diosmin-type products reduced leg swelling compared with placebo. Many of the individual trials were fairly small, and the size of the benefit was moderate at best.
- Best evidence:
Ulcerative Colitis
Ulcerative colitis is an inflammatory bowel disease in which the colon and rectum stay chronically inflamed and ulcerated, causing bloody diarrhea, abdominal pain, and urgency during flares. Resveratrol and curcumin have the clearest trial results: symptoms improved with resveratrol in one small trial, and inflammation went down with curcumin across three studies. Those studies were small, and the evidence for curcumin is limited, so it's too early to say how much either helps.
- Best evidence:
Acute Respiratory Infection (ARI)
Acute respiratory infections, such as colds, flu and bronchitis, are mostly viral infections of the nose, throat and airways, where the immune response brings on inflammation, extra mucus and cough. The evidence is strongest for zinc, where a large review of trials found a lower risk of these infections, and moderate for Pelargonium sidoides, where bronchitis symptoms eased. The Pelargonium studies were small, though, and vitamin C showed no clear difference in infection risk.
- Best evidence:
Cardiomyopathy
Cardiomyopathy is a group of heart muscle diseases, including enlarged, thickened, or stiff forms, that make it harder for the heart to pump blood. Coenzyme Q10 and omega-3 fatty acids have the strongest evidence among supplements, yet two small trials of coenzyme Q10 found no clear difference in exercise tolerance. Idebenone eased signs of heart thickening in some people with Friedreich's ataxia, but that evidence is limited and applies to a narrow group.
- Best evidence:
Chemotherapy Side Effects
Chemotherapy side effects arise because drugs aimed at fast-dividing cancer cells also hit healthy fast-dividing cells in the gut, bone marrow, hair follicles and nerves. Probiotics have the strongest evidence, and trials found appetite went up, while ginger added to usual anti-nausea medicines eased nausea and vomiting, with moderate evidence. One small lemon balm trial found no clear difference in nerve pain, and most other options have limited evidence.
- Best evidence:
Major Depressive Disorder (MDD)
Major depression involves shifting brain chemistry, inflammation, oxidative stress and weaker connections between neurons, not simply low serotonin. Among supplements, the evidence is strongest for curcumin, where anxiety symptoms improved in people with depression, followed by vitamin D, where depression symptoms improved, and omega-3s, which also eased anxiety. Most of these studies were small, and only curcumin's evidence reaches moderate.
- Best evidence:
Appetite Regulation
Appetite regulation is the body's hunger and fullness system, where hormones like ghrelin, leptin, GLP-1 and PYY pass signals between gut, brain and fat tissue. The evidence is strongest for glucomannan, a fiber that swells in the stomach, and for protein, while small trials of 5-HTP from Griffonia found more fullness and less eating. Those 5-HTP studies were tiny, and green tea extract showed no clear difference in ghrelin.
- Best evidence:
Attention Deficit Hyperactivity Disorder (ADHD)
ADHD is a neurodevelopmental condition marked by inattention, hyperactivity, and impulsivity, tied to brain regions that manage planning and focus and that rely on dopamine and norepinephrine. Among supplements, fish oil and L-carnitine have the strongest support, and small trials found ADHD symptoms improved with each, backed by moderate evidence. Most of these studies were small, and essential fatty acid results were inconsistent, so stimulant medication remains the most effective option.
- Best evidence:
Chronic pain
Chronic pain is pain that lasts beyond three to six months, as changes in the nervous system leave the pain system oversensitive. Omega-3 fatty acids and vitamin D have the most support among supplements, rated moderate, and a trial of the spinal drug ziconotide found a modest edge over placebo for pain intensity. Even so, that gain was small, and N-acetylcysteine showed no clear difference for pain in the one study reviewed.
- Best evidence:
Cognitive Function
Cognitive function is the brain's ability to remember, focus, plan, and think quickly, all relying on nerve cells communicating well. The best-supported options are tesamorelin and sermorelin, and trials found that months of treatment improved executive function and tests of working memory, planning, attention, and processing speed in older adults. Those trials were small, though, and most other research, including on humanin and semax, came from animals or lab studies.
- Best evidence:
Frailty
Frailty is a state of reduced resilience in which a minor event, like an infection or a medication change, can trigger a big drop in everyday function. The evidence is rated strongest for protein and vitamin D, though whey protein trials in about 1,400 people found no clear difference in function. A small zinc study found function improved, but that evidence is limited.
- Best evidence:
Respiratory Health
Respiratory health is how well your lungs and airways move oxygen and how well your immune defenses handle infections and irritants. The evidence is strongest for vitamin D and N-acetyl cysteine, and in a trial of a tyrothricin throat lozenge, more people with acute pharyngitis reached complete remission by 72 hours than on placebo. A study of about 5,700 people found no clear difference for vitamin D in lower respiratory infections.
- Best evidence:
Diabetic Neuropathy
Diabetic neuropathy is nerve damage from long-term high blood sugar, which harms nerves through oxidative stress, sugar-related compounds called AGEs, and poorer blood flow, often causing numbness, tingling or burning in the feet and hands. Among supplements, the evidence is strongest for alpha-lipoic acid, with moderate evidence for benfotiamine and acetyl-L-carnitine. Still, the detailed results were thin: one benfotiamine study of 82 people found no clear difference in AGEs.
- Best evidence:
Football Performance
Football, whether soccer or American, asks the body for endurance, speed, power, agility and the ability to repeat hard efforts again and again. Creatine has the strongest evidence among supplements for those explosive, repeated efforts, and in a small study of 20 people beta-alanine eased fatigue symptoms. Still, findings here are sparse and small, and HMB showed no clear difference in anaerobic capacity in 28 people, so the picture is far from settled.
- Best evidence:
Oligospermia
Oligospermia is a low sperm count, a common contributor to male infertility that can stem from hormone imbalances, varicocele, infections, heat, or oxidative stress. The evidence is strongest for L-carnitine, where research in 338 men found fertility improved, while tribulus showed limited signs of better erections. Those studies were small to moderate in size, and the tribulus findings concern erections rather than sperm count itself.
- Best evidence:
Rugby Performance
Rugby is a contact sport that demands strength, power, speed, endurance and recovery from repeated impacts. Creatine and caffeine carry the strongest evidence for sports like this, and small trials found creatine improved alertness while sodium bicarbonate improved anaerobic capacity. Those specific findings are limited, though, since the studies were small and some bicarbonate work involved swimmers rather than rugby players.
- Best evidence:
Colorectal Cancer
Colorectal cancer is a cancer of the colon or rectum, where cells in the bowel lining grow out of control. Probiotics and ginger have moderate evidence behind them, though probiotic trials on bloating gave mixed results, and a small study of 30 people found ginger extract improved a measure of colorectal cancer risk. That ginger study involved people at normal risk, so it says little about those already in treatment.
- Best evidence:
Parkinson's Disease
Parkinson's disease is a progressive condition in which dopamine-producing neurons in a brain area called the substantia nigra die off, leading to tremor, stiffness, slowed movement and balance problems. Among supplements, the evidence is strongest for Mucuna pruriens, a natural source of L-DOPA, and symptoms improved in a few small trials, while vitamin D showed moderate evidence, with better six-minute walking performance. Those Mucuna studies were small, and creatine showed no clear difference in symptoms, so the picture is still early.
- Best evidence:
Candidemia and Invasive Candidiasis
Candidemia and invasive candidiasis are infections where Candida yeast, normally harmless on skin and in the gut, reaches the bloodstream and organs. The evidence is strong for anidulafungin, which achieved treatment success in 76% of people versus 60% with fluconazole, and for rezafungin, which matched caspofungin at day 14. Rezafungin showed similarity rather than an advantage, so it looks comparable, not better.
- Best evidence:
Chronic Liver Disease
Chronic liver disease is long-lasting liver damage, where inflammation and scarring gradually interfere with filtering blood and making bile. S-adenosylmethionine has the most research behind it, but a review found no clear difference in bilirubin, while liver cell content went up with TUDCA in one small study. That study involved only five people, so the evidence overall is limited.
- Best evidence:
Eczema (Atopic Dermatitis)
Eczema, or atopic dermatitis, is an inflammatory skin condition that leaves skin dry, itchy and red, and it often runs alongside asthma and allergies. Probiotics and vitamin D have the most research behind them, rated moderate, yet studies found no clear difference in allergic disease risk or respiratory infection symptoms, while a small study of nicotinamide found redness improved. Most of this evidence is limited, so the picture is still early.
- Best evidence:
Hyperuricemia
Hyperuricemia means too much uric acid in the blood, produced when the body breaks down purines from certain foods and drinks, and it can lead to gout and kidney stones. Vitamin C and tart cherry extract have moderate evidence, and vitamin C lowered uric acid in studies. A small trial of tart cherry concentrate found no clear difference in gout symptoms, and IP6 lowered uric acid in only 25 people.
- Best evidence:
Runners' Health
Running strains the body through repeated impact, heavy sweat losses and high oxygen demands, so runners often face low iron, bone stress injuries and slow recovery. The evidence is strongest for iron, vitamin D and caffeine, and a meta-analysis found caffeine improved running performance. Findings for other options were thinner: one small rhodiola study saw the inflammation marker CRP go down, and colostrum showed no clear difference in cyclists.
- Best evidence:
Acne
Acne happens when hair follicles clog with oil and dead skin cells, letting bacteria thrive and the skin become inflamed, and hormones that boost oil explain why it often flares in puberty. The evidence is strongest for nicotinamide and zinc, and in three nicotinamide studies, acne symptoms improved. Those trials were fairly small and mostly compared a nicotinamide gel with an antibiotic gel, while tea tree oil and selenium have only limited evidence.
- Best evidence:
Crohn's Disease
Crohn's disease is a form of inflammatory bowel disease in which ongoing inflammation can strike any part of the digestive tract, most often the end of the small intestine. Vitamin D and omega-3 fatty acids have the strongest evidence among supplements, rated moderate, since low vitamin D is very common and omega-3s may calm inflammation. Tiny studies of glutamine, curcumin, and cannabis found no clear difference, so those remain very limited.
- Best evidence:
Cystic Fibrosis
Cystic fibrosis is a genetic condition in which thick, sticky mucus clogs the airways and keeps digestive enzymes from reaching the intestines. Pancreatic enzymes and vitamin D have the strongest evidence for supporting nutrition, and a trial found vitamin E raised blood vitamin E levels. That vitamin E evidence is limited, from one small study, and probiotics showed no clear difference in symptoms.
- Best evidence:
H. Pylori Infection
H. pylori is a spiral-shaped bacterium that lives in the stomach lining, where it survives acid and can cause inflammation, gastritis, and ulcers. Probiotics have the strongest evidence, and abdominal pain eased in trials, while Lactobacillus reuteri, with moderate evidence, improved signs of infection across three studies. Those benefits were small, and the L. reuteri studies were few and mostly tested it alongside standard antibiotic therapy.
- Best evidence:
Myalgic Encephalomyelitis (Chronic Fatigue Syndrome)
ME/CFS is a long-term illness in which deep exhaustion does not ease with rest and often flares after exertion, possibly tied to disrupted cellular energy and immune signaling. Among supplements, L-carnitine and D-ribose drew the most interest, and small studies found attention improved with carnitine and fatigue eased with D-ribose. The evidence is limited, though, since those studies were small, with 90 and 36 people.
- Best evidence:
Alcohol Use Disorder
Alcohol use disorder is a medical condition where people can't stop or control drinking despite harm, while long-term alcohol use damages the liver and brain and depletes nutrients. B vitamins and NAC have the strongest evidence ratings among supplements, and a small trial found acetyl-L-carnitine improved alcohol dependence symptoms. That carnitine result came from one pilot study of 64 people, so the evidence is limited.
- Best evidence:
Hashimoto's disease
Hashimoto's disease is an autoimmune condition in which the immune system gradually attacks the thyroid gland, cutting the hormones it makes and often causing an underactive thyroid. Among supplements, selenium has the strongest evidence, but studies of Hashimoto's signs found no clear difference, and one small carnitine study found bone density improved. Vitamin D has moderate evidence, yet most findings come from small studies, so conclusions remain tentative.
- Best evidence:
Hepatic Encephalopathy
Hepatic encephalopathy is brain dysfunction caused by liver disease, when a struggling liver can't clear toxins such as ammonia from the blood. The evidence is strongest for L-carnitine, where five studies found blood ammonia went down, while resveratrol, with moderate evidence, was linked to lower blood urea nitrogen. Those studies were small to moderate in size and tracked lab markers, so they say less about thinking or daily function.
- Best evidence:
Hypoactive Sexual Desire Disorder
Hypoactive sexual desire disorder is persistently low sexual desire that causes personal distress, shaped by brain signaling, hormones, mood, and stress. Bremelanotide has the strongest evidence: two large trials of about 1,200 women found improved desire scores compared with placebo across all subgroups. Maca and DHEA have moderate evidence, but tribulus and other options are limited, and a small nicotine trial found no clear difference in libido.
- Best evidence:
Multiple Myeloma
Multiple myeloma is a cancer of plasma cells, the antibody-making immune cells in bone marrow, which crowd out healthy blood cells. Evidence is strongest for bortezomib and carfilzomib: trials in relapsed disease found bortezomib produced responses in 38% versus 18% on a steroid, and carfilzomib added to standard drugs extended time without progression from 17.6 to 26.3 months. Motixafortide, also strongly studied, was tested for collecting stem cells before transplant instead.
- Best evidence:
Sarcopenia
Sarcopenia is the age-related loss of muscle mass, strength, and function, driven by less activity, too little protein, and muscles that respond poorly to growth signals. Protein and creatine have the strongest evidence among supplements, and whey protein trials found body fat went down. That whey finding is limited, though: the studies were small, and HMB and nicotinamide mononucleotide showed no clear difference in body fat or muscle mass.
- Best evidence:
Stable Angina
Stable angina is predictable chest pain or pressure during exertion or stress, caused by too little blood reaching the heart muscle. Coenzyme Q10 and L-carnitine have the strongest evidence, rated moderate, and both are thought to support the heart's energy supply; L-carnitine trials have been pooled in a meta-analysis. Still, a single study of Terminalia arjuna found no clear difference in exercise tolerance, and evidence for it is very limited.
- Best evidence:
Aging & Longevity
Aging is the gradual decline in how well the body's cells make energy and repair themselves. The evidence is moderate for two peptides: humanin extended lifespan in worms, and its levels were higher in the children of centenarians, while MOTS-c eased age-related muscle insulin resistance in older mice. Nearly all of this is animal or lab work, so it says little yet about people.
- Best evidence:
Constipation
Constipation happens when stool moves too slowly through the colon, so extra water is absorbed and stools turn hard and difficult to pass. The evidence is strongest for linaclotide and plecanatide, and trials found people had more complete spontaneous bowel movements each week than those on placebo, with linaclotide also improving stool consistency and reducing straining. Gentler options like psyllium, senna and jujube have limited evidence, mostly from a few small studies.
- Best evidence:
COVID-19
COVID-19 is an illness caused by the SARS-CoV-2 virus, ranging from no symptoms to fever, cough and fatigue, and in some people severe lung illness with pneumonia and blood clots. Vitamin D is the most studied supplement for it, yet the one study reviewed found no clear difference in deaths from any cause. That evidence is very limited, and vitamin C, zinc and quercetin have only limited research behind them so far.
- Best evidence:
Hypoadrenalism
Hypoadrenalism, or adrenal insufficiency, happens when the adrenal glands make too little cortisol, because they are damaged (Addison's disease) or because the pituitary sends too little ACTH to switch them on. Among supplements, DHEA and salt have the strongest support, both moderate, though one small DHEA trial found no clear difference in body fat. Diagnosis stands on firmer ground: a cosyntropin test detected primary cases with about 97% sensitivity.
- Best evidence:
Hypothyroidism
Hypothyroidism is when the thyroid gland makes too little T3 and T4, hormones that set the pace of metabolism, so tiredness, feeling cold, weight gain and brain fog can follow. Ashwagandha and L-carnitine have the most research, and in small trials T3 went up with ashwagandha while blood glucose improved with L-carnitine. The evidence is limited for both, with only 50 to 60 people studied.
- Best evidence:
Lower Respiratory Tract Infection
Lower respiratory tract infections affect the bronchi and lungs, below the voice box, and include bronchitis, bronchiolitis and pneumonia. Vitamin C and vitamin D are the leading candidates, yet vitamin D showed no clear difference in lower respiratory infection risk among 5,110 people, and a nasal resveratrol solution showed none for upper infections in 39 children. Evidence for each is very limited, and the other supplements studied have little direct trial data here.
- Best evidence:
Psoriasis
Psoriasis is a chronic autoimmune condition in which the immune system pushes skin cells to build up too fast, causing red, scaly, inflamed patches. Omega-3 fatty acids and vitamin D have the strongest support among supplements, each with moderate evidence, though reviews of probiotics found mixed results on CRP, a blood marker of inflammation. Most other options rest on limited evidence, small studies, or mouse work, so conclusions stay tentative.
- Best evidence:
Acromegaly
Acromegaly is a hormone condition in which the pituitary, usually through a benign tumor, makes too much growth hormone, gradually enlarging the hands, feet, and face. The evidence is strong for pegvisomant, octreotide, and lanreotide: trials found most people on pegvisomant reached normal IGF-1, while about half to 60% reached growth hormone control on the other two. Those results track hormone levels, not symptoms.
- Best evidence:
Autism Spectrum Disorder (ASD)
Autism spectrum disorder (ASD) is a neurodevelopmental condition that begins in early childhood. It affects a person’s ability to interact socially, communicate, and learn. ASD comes with varying degrees of differences, which is why it is called a “spectrum” disorder.
- Best evidence:
Acute Bronchitis
Acute bronchitis is inflammation of the airways leading to the lungs, usually set off by a viral infection, and it brings a lingering cough, often with mucus, for one to three weeks. Among supplements, the evidence is strongest for Pelargonium sidoides, and trials found bronchitis symptoms improved, with N-acetylcysteine showing moderate support too. Those pooled results came from a modest number of studies, and the N-acetylcysteine data leaned on a single review that looked at chronic bronchitis.
- Best evidence:
Hepatitis C
Hepatitis C is a viral infection of the liver that can cause ongoing inflammation and, over time, damage. Among supplements, TUDCA, a bile acid, has the most research behind it, and in one very small study of five people, liver cell content went up. That evidence is limited, and it shows nothing yet about the virus itself or how people felt, so the picture is still early.
- Best evidence:
Immune Function
Immune function is how well the body's white blood cells, tissues, and chemical signals recognize germs and damaged cells and respond to them. Thymosin alpha-1 and LL-37 have the most support, with moderate evidence: T-cell counts went up with thymosin alpha-1, and LL-37 was active against many bacteria, fungi, and viruses. Much of the cited work was in the lab, though, and the evidence for other options is limited.
- Best evidence:
Pain Relief
Pain is an experience shaped by both tissue damage and how the nervous system processes signals, and chronic pain can wear down daily life. Topical capsaicin has the strongest evidence, with curcumin at a moderate level, and one trial of about 1,500 people found headaches improved with caffeine alongside acetaminophen after spinal anesthesia. Cannabis and serrapeptase have only limited evidence from small studies, so their results remain uncertain.
- Best evidence:
Sexual Dysfunction
Sexual dysfunction means ongoing trouble with sexual desire, arousal, or function, and it can stem from hormonal changes, heart disease, diabetes, antidepressants, or stress. Among supplements, maca has some research behind it, and a small pilot study in sportsmen found their sexual desire went up. That study included only 20 people, so the evidence is limited and it is too early to say who else might see the same.
- Best evidence:
Skin and Soft Tissue Infections
Skin and soft tissue infections are bacterial infections of the skin and the tissue beneath it, where germs such as staph invade and cause redness, swelling and pain. The antibiotics dalbavancin, oritavancin and telavancin have the strongest evidence, with trials finding clinical success in roughly 80 to 88 percent of people, about the same as vancomycin. These drugs matched standard therapy rather than beating it, in trials of acute or complicated infections.
- Best evidence:
Sleep Quality
Sleep quality reflects how easily you fall asleep, how well you stay asleep, and how rested you feel, all guided by the brain's body clock and calming signals such as GABA. Tryptophan has the most support: trials found people fell asleep sooner, especially those with mild insomnia, while small studies of the peptide DSIP found total sleep time went up. Still, evidence beyond tryptophan is limited, and studies were small or mostly animal work.
- Best evidence:
Cirrhosis
Cirrhosis is advanced scarring of the liver, left by long-term damage from alcohol, viral hepatitis, or fatty liver disease, which leaves the organ less able to filter blood and make proteins. Among supplements, L-carnitine has some of the better-supported findings, and in five studies blood ammonia went down, a toxin that builds up when the liver struggles. Those studies were small, covering only 76 people, so the evidence is moderate at best.
- Best evidence:
Lactation (Breast Milk Production)
Lactation is the body's making of breast milk, driven by hormones like prolactin and oxytocin and by how often and how well milk is removed from the breast. Among supplements, fenugreek has the most support, and the evidence is moderate: two small trials found milk production went up in mothers using a fenugreek tea. Those studies were small and short, and shatavari and milk thistle showed no clear difference in milk production, so the evidence for most herbs is thin.
- Best evidence:
Mitochondrial Myopathy
Mitochondrial myopathy is a muscle condition where mitochondria, the cell's energy makers, work poorly, so muscles tire easily. Creatine and L-carnitine have the most research, and small studies found symptoms eased with creatine and exercise capacity improved with L-carnitine. The evidence is limited, though: the creatine study followed only four children, and the carnitine work twelve people.
- Best evidence:
Neuroendocrine Tumors
Neuroendocrine tumors are growths that arise from hormone-producing cells, most often in the gut, pancreas, or lungs, and many grow slowly. Octreotide, lanreotide, and lutetium-177 dotatate have the strongest evidence, and large trials found tumors took longer to progress, with the risk of progression or death falling by 79% in one lutetium study. Much of this work involved advanced midgut tumors, so results may not apply to every type.
- Best evidence:
Amyotrophic Lateral Sclerosis
ALS, sometimes called Lou Gehrig's disease, is a progressive condition in which motor neurons, the nerve cells that control voluntary muscles, die, leading to weakness, muscle wasting, and eventually paralysis. Creatine has the most human trial data: six studies with 386 people found no clear difference in ALS symptoms. The evidence is very limited overall, and one mouse study of 7,8-dihydroxyflavone that preserved motor performance says little about people.
- Best evidence:
Arthritis (Multiple Kinds)
Arthritis is joint inflammation, most often osteoarthritis, where cartilage wears down, or rheumatoid arthritis, where the immune system attacks the joints. Omega-3 fatty acids and curcumin have the strongest evidence for easing joint pain and inflammation, and in rheumatoid arthritis, GLA from evening primrose or borage oil reduced pain, swelling and morning stiffness. Thunder god vine lowered rheumatoid disease activity, though toxicity concerns limit it, and most other options have less evidence.
- Best evidence:
Blood Health
Blood health is how well your blood carries oxygen, helps defend against infection and keeps circulating, which depends on healthy red and white cells. The strongest evidence is for pegcetacoplan, which improved hemoglobin more than the standard drug eculizumab in a large trial in paroxysmal nocturnal hemoglobinuria. Beyond that, evidence is limited: chlorophyllin improved white blood cell counts in one trial of 105 people, but most other work is small or in animals.
- Best evidence:
Cancer-Related Fatigue
Cancer-related fatigue is a persistent, overwhelming exhaustion that rest does not relieve, driven by the cancer, its treatments, anemia, inflammation, poor sleep and stress. Among supplements, the evidence is strongest for American ginseng, and trials found fatigue eased; coenzyme Q10 has moderate evidence too. Much of the rest is thinner, and Dang Shen, a traditional herb, has mostly been studied in animals, where endurance improved, with no human trials.
- Best evidence:
Ischemic Heart Disease
Ischemic heart disease, also called coronary artery disease, happens when the coronary arteries narrow or become blocked, so the heart muscle gets less blood than it needs. Among supplements, omega-3 fatty acids and coenzyme Q10 have the best-rated evidence, and in two small trials of coenzyme Q10, blood flow went up. Those studies included only 33 people in total, so the evidence for that result is limited.
- Best evidence:
Menstrual Health
Menstrual health covers painful periods, heavy bleeding, premenstrual syndrome and irregular cycles, often tied to prostaglandin imbalances, hormone shifts and nutrition. Magnesium and ginger have the most research, with moderate evidence, and some studies found ginger eased period pain about as well as common anti-inflammatory painkillers. The evidence is thinner elsewhere: iron showed limited evidence of lower anemia risk, and most other options have only limited data.
- Best evidence:
Myotonic Dystrophy Type 1
Myotonic dystrophy type 1 is an inherited condition caused by a repeated DNA stretch in the DMPK gene, leaving muscles slow to relax and gradually weaker, and sometimes affecting the heart and eyes. Creatine has been studied for it, but the only research found no clear difference in bilirubin. The evidence is very limited, just one study of 34 people, so it says little about strength or daily symptoms.
- Best evidence:
Systemic Lupus Erythematosus
Systemic lupus erythematosus is a long-term autoimmune disease in which the immune system attacks the body's own tissues, causing inflammation in the skin, joints, kidneys and elsewhere, often in flares. Trials of curcumin found blood pressure improved, while a fish oil trial found no clear difference in blood flow. Both findings rest on small studies, only 24 people for curcumin and 60 for fish oil, so the evidence is limited at best.
- Best evidence:
Wrestling Performance
Wrestling performance rests on strength, power, endurance, and technique, plus careful weight management. The evidence is strongest for creatine and caffeine, which are looked at for power, strength, and repeated high-intensity efforts, while beta-alanine has moderate support. Findings on body fat were thinner: beta-alanine showed no clear difference in 37 people, and chromium and zinc results came from very small studies.
- Best evidence:
Diabetic Retinopathy
Diabetic retinopathy is a diabetes complication that damages the blood vessels in the retina, and it is the leading cause of blindness in working-age adults. Vitamin D and omega-3 fatty acids are the main supplements studied, though the evidence is limited, and one small study found probiotics improved blood glucose. That result is about blood sugar, not eyesight, so it's too early to say what any supplement does for the retina.
- Best evidence:
Lactose Intolerance
Lactose intolerance happens when the body makes too little lactase, the enzyme that digests lactose, so undigested milk sugar ferments in the gut and causes uncomfortable symptoms. The evidence is strongest for lactase enzyme supplements, and bloating improved in trials of people using them. That finding rests on a fairly small group of 66 people, while the evidence for Lactobacillus probiotics is moderate.
- Best evidence:
Malnutrition
Malnutrition happens when the body doesn't get the nutrients it needs to work properly, whether from too little food, poor absorption, or higher needs. The evidence is strongest for high-calorie nutritional supplements and protein supplements, which supply concentrated energy and the building blocks for tissue repair. Studies of probiotics and synbiotics found no clear difference in height, and that evidence is very limited.
- Best evidence:
Multidrug-Resistant Bacterial Infections
Multidrug-resistant infections arise when bacteria adapt to withstand several common antibiotics, leaving fewer medicines that work. Colistin and polymyxin B, older last-resort antibiotics, have the strongest evidence: pooled trials found colistin useful against resistant Gram-negative bacteria, and about 70% of people given polymyxin B in one study were alive after 14 days. The colistin trials were few and small, and the polymyxin B work was observational.
- Best evidence:
Pneumonia
Pneumonia is a lung infection, caused by bacteria, viruses, or fungi, that inflames the air sacs in one or both lungs. Vitamin D and vitamin C are the best-studied supplements for it, but a trial of 653 people found no clear difference in pneumonia symptoms with vitamin D, and vitamin C showed none in deaths from any cause. Each finding comes from one study, so the evidence is very limited.
- Best evidence:
Preeclampsia
Preeclampsia is a serious pregnancy complication, usually appearing after 20 weeks, in which blood pressure climbs and protein shows up in the urine. Calcium and vitamin D have the strongest evidence, and reviews found a lower risk of preeclampsia with both, with moderate-sized effects. The calcium benefit looked clearest in women with low dietary calcium, while the vitamin D finding rested on a single study.
- Best evidence:
Radiation Therapy Side-Effects
Radiation therapy damages cancer cells but also nearby healthy tissue, which can cause skin redness and peeling, mouth sores, diarrhea and fatigue that usually fade after treatment. Among supplements, trials found less severe skin inflammation with hyaluronic acid (moderate evidence) and a lower dermatitis risk with calendula (limited evidence). Those findings rest on small numbers, and one calendula trial found no difference from a plain cream, while aloe vera showed no effect.
- Best evidence:
Restless Leg Syndrome
Restless legs syndrome is a neurological condition causing an irresistible urge to move the legs, with crawling or tingling feelings that flare at rest and at night. The evidence is strongest for iron, since low iron is closely linked to the condition and the brain needs iron to make dopamine; a magnesium study found no clear difference in sleep problems. That result came from just 10 people, so it says little either way.
- Best evidence:
Acute Kidney Injury
Acute kidney injury is a sudden drop in kidney function over hours to days, often after reduced blood flow, direct kidney damage, or a urinary blockage. Vitamin E has moderate evidence, with fewer cases of kidney injury reported, and among people in shock, angiotensin II was linked to more coming off dialysis and surviving 28 days. That angiotensin II result came from a follow-up analysis still needing confirmation.
- Best evidence:
Athletic Performance
Athletic performance is how well your body handles exercise, shaped by strength, endurance, hydration and recovery. The evidence is moderate for electrolytes, as trials found sodium-containing drinks helped people retain fluid and restore body water after exercise better than plain water. Thai ginseng improved grip strength in two small trials of athletes, but the evidence is limited, and most other options rest on small studies or animal work.
- Best evidence:
Duchenne Muscular Dystrophy
Duchenne muscular dystrophy is a severe genetic disease, mostly in boys, where mutations in the dystrophin gene leave muscle fibers fragile and steadily weaker. Vitamin D and calcium have the most backing, with moderate evidence tied to bone health during long-term corticosteroid use, and in creatine studies blood creatinine went up. Creatine research was small, about 30 people across three studies, so that evidence is limited.
- Best evidence:
Hereditary Angioedema
Hereditary angioedema is a rare inherited condition in which too little working C1 inhibitor protein lets bradykinin build up, causing sudden swelling in the skin, gut, or airway. The evidence is strongest for two prescription medicines: icatibant cut symptoms by half in about 2 hours versus nearly 20 on placebo, and ecallantide improved symptoms more than placebo at 4 hours. Those trials measured relief during attacks, not supplements.
- Best evidence:
Intermittent Claudication
Intermittent claudication is leg pain during walking that eases with rest, caused by peripheral artery disease, in which narrowed arteries limit blood flow to the legs. Ginkgo biloba and L-arginine have the strongest evidence, rated moderate, and in one trial of 39 people, blood flow went up with L-arginine. That study was small, and the evidence for other options such as vitamin E is limited.
- Best evidence:
Low Birth Weight
Low birth weight means a baby is born smaller than the healthy range, often because of limited nourishment before birth, which raises the odds of later health problems. Prenatal multivitamins, iron and folic acid have the strongest evidence overall, yet for birth weight itself, iron studies found a change without a clear direction and folic acid results were mixed. Zinc showed no clear difference, and the iron findings came from one small review.
- Best evidence:
Neurasthenia
Neurasthenia is an older diagnosis for lingering fatigue, weakness, irritability and poor concentration, now often described as burnout or chronic fatigue. Bromantane has the most research, and trials found asthenic symptoms, meaning weakness and exhaustion, eased, including in one placebo-controlled study; a small reishi study also found fatigue improved. Those studies were few and fairly small, so the evidence is moderate for bromantane and limited for reishi.
- Best evidence:
Premature Birth
Premature birth is delivery before 37 weeks of pregnancy, often linked to infection, inflammation, a short cervix, or carrying more than one baby. Folate and omega-3 fats have drawn the most research, but reviews of folic acid found mixed results for birth weight, and omega-3 showed no clear difference in infant death risk. The evidence is limited overall, and any benefit may matter most for women who are low in key nutrients.
- Best evidence:
Chronic Mountain Sickness (CMS)
Chronic mountain sickness, or Monge's disease, develops over months or years at high altitude, when the body overproduces red blood cells to offset low oxygen. Iron has the strongest evidence among supplements, rated moderate across about 350 people, with vitamin D behind it at limited. Balance matters, since too much iron can push red cell counts higher, and the evidence for other options, including maca, is limited at best.
- Best evidence:
Glaucoma
Glaucoma is a group of eye conditions in which the optic nerve is damaged, usually because pressure inside the eye is too high, and lost vision cannot be regained. Citicoline has the strongest evidence, rated moderate, and one small study of 60 people found better visual acuity; omega-3s are limited. That rests on one small study, and ginkgo, coenzyme Q10 and others have only limited research.
- Best evidence:
Obsessive-Compulsive disorder (OCD)
OCD is a mental health condition in which unwanted, intrusive thoughts lead to repetitive behaviors done to ease anxiety. N-acetyl cysteine has the most research, with moderate evidence as an add-on to standard care, while inositol had limited evidence, with small studies finding anxiety symptoms improved. Those inositol studies included just 13 people and focused on panic disorder and binge eating rather than OCD, so the results are early.
- Best evidence:
Post-Traumatic Stress Disorder (PTSD)
PTSD is a condition that can follow a traumatic event, when the brain's fear circuitry and stress hormone systems stay on high alert, bringing flashbacks, nightmares and poor sleep. Among supplements, lavender has the one set of trial results so far: across four studies, anxiety symptoms improved, though the evidence is limited. Those studies included only 47 people and looked at anxiety in dental settings, so they say little about PTSD itself.
- Best evidence:
Sepsis
Sepsis is a life-threatening emergency in which the body's response to an infection triggers widespread inflammation and organ damage. Among supplements, thymosin alpha-1 has the most support, and studies found that deaths within 28 days went down. That evidence is moderate, drawn from three studies of 890 people, and the only other survival finding, for LL-37, came from mouse models, so human evidence remains thin.
- Best evidence:
Traumatic Brain Injury
Traumatic brain injury ranges from mild concussion to severe damage, and after the first blow, inflammation, oxidative stress and energy failure keep harming the brain for days to weeks. Creatine has the clearest finding so far, as dizziness eased in a small pilot study of people after head injury. With only 35 people in one study, the evidence is limited and larger trials are needed.
- Best evidence:
Volleyball Performance
Volleyball performance rests on repeated jumps, fast reactions and long rallies, which load the legs, shoulders and core. Creatine, caffeine and beta-alanine have the strongest evidence for power, jump height and repeated jumping, including a beta-alanine meta-analysis on sprint and jump performance. Volleyball-specific results are thin, though: the only volleyball study of HMB, in 29 people, found no clear difference in cortisol.
- Best evidence:
Vulvovaginal Candidiasis (Yeast Infection)
A yeast infection, or vulvovaginal candidiasis, happens when Candida yeast overgrows in the vagina, bringing itching, burning, redness, and thick white discharge. People mostly look at Lactobacillus probiotics and vaginal boric acid, which have the strongest support, with moderate evidence for each, as ways to restore a healthy vaginal balance. Evidence for vitamin D, garlic, tea tree oil, oregano oil and others is limited, and the studies were small.
- Best evidence:
Acute Coronary Syndrome (ACS)
Acute coronary syndrome covers heart attacks and unstable angina, which happen when a ruptured plaque and blood clot suddenly cut blood flow in a coronary artery. Among supplements, omega-3 fatty acids have the strongest evidence, followed by coenzyme Q10. A small curcumin trial of 63 people found HDL cholesterol improved, but evidence for creatinol O-phosphate is limited and mostly animal or lab work.
- Best evidence:
Acute Gastroenteritis
Acute gastroenteritis is inflammation of the stomach and intestines, usually from a virus or bacteria, causing diarrhea and vomiting that mostly pass within days. Probiotics, including Saccharomyces boulardii, have the strongest support, and trials found diarrhea symptoms improved, with one in hospitalized children finding a Lactobacillus acidophilus mixture shortened and eased diarrhea. The studies were modest in size and mostly in children, so the evidence is moderate.
- Best evidence:
Acute Nonspecific Knee Pain
Acute nonspecific knee pain is knee soreness without an obvious structural cause like a ligament tear, often from overuse, strain, or muscle imbalance. Among supplements, bromelain, boron, and glucosamine have the most to show: inflammation went down with bromelain, knee pain improved with boron, and rehabilitation rates improved with glucosamine. Still, the evidence is limited, since these studies were small, with 60 to 102 people each.
- Best evidence:
Allergic Diseases (General)
Allergic diseases arise when the immune system overreacts to harmless things like pollen, dust mites, or foods, releasing histamine and other chemicals that cause sneezing, itching, and swelling. Probiotics are among the best-supported supplements, with moderate evidence, and trials of one strain, Lactobacillus acidophilus L-92, found eczema symptoms eased in children and adults. Those studies were small, though, and most plant extracts have only been tested in animals or cells.
- Best evidence:
Binge Eating Disorder
Binge eating disorder involves repeated episodes of eating large amounts of food while feeling out of control, tied to how the brain handles reward, mood and appetite. Chromium and inositol have the most research, and in small trials binge eating eased with chromium while anxiety symptoms eased with inositol. The evidence is limited for both, and the studies were small, so it is too early to say how well the findings hold up.
- Best evidence:
Brain Tumor
A brain tumor is a growth of abnormal cells that either starts in the brain, as with gliomas and meningiomas, or spreads there from another cancer. Among supplements, Boswellia stands out, and one finding showed tumor size improved, while a small ginkgo study in people who had received radiation found no clear difference in attention. The evidence is limited, with very few small studies, so these are early signals.
- Best evidence:
Flu
Flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs, bringing fever, body aches, and deep tiredness. People most often look at vitamin D and elderberry, and a meta-analysis of elderberry examined upper respiratory symptoms, while two small analyses found asthma symptoms improved with vitamin D. Still, the vitamin D evidence is limited and neither result tested flu itself, so the picture remains unsettled.
- Best evidence:
Growth Hormone Deficiency
Growth hormone deficiency occurs when the pituitary gland makes too little growth hormone, which drives growth in children and helps adults maintain muscle, bone and metabolism. The strongest evidence is for macimorelin, an oral test that trials found identified adult cases with accuracy comparable to the standard insulin tolerance test. CJC-1295 raised growth hormone levels in healthy adults, but that evidence is moderate and measured hormone levels rather than patient outcomes.
- Best evidence:
Inflammatory Bowel Disease (IBD)
Inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis, is a long-term condition in which the immune system attacks the gut lining, causing inflammation, diarrhea, belly pain and fatigue. Among supplements, resveratrol has the best-supported findings, and symptoms improved in a small study. Curcumin showed no clear difference for Crohn's symptoms, and the resveratrol evidence is only moderate.
- Best evidence:
Lung Cancer
Lung cancer is a disease in which cells in the lungs grow out of control and form tumors that can interfere with breathing and spread elsewhere. Omega-3 fatty acids and vitamin D have moderate evidence among supplements, yet fish oil studies found no clear difference in C-reactive protein, an inflammation marker. Those studies were tiny, and beta-carotene in smokers went the other way: trials found a higher risk of lung cancer.
- Best evidence:
Mitochondrial Cytopathy
Mitochondrial cytopathy is a group of disorders in which mitochondria, the tiny structures that make cellular energy, work poorly, mostly affecting the brain, muscles and heart. Coenzyme Q10 is the most studied supplement for it, alongside creatine, but trials found no clear difference in exercise tolerance or aerobic exercise measures. Those studies were very small, about 30 people for coenzyme Q10 and just 7 for creatine, so the evidence is very limited.
- Best evidence:
Nephrotic Syndrome
Nephrotic syndrome is a kidney condition in which the filtering units, the glomeruli, become damaged and let large amounts of protein leak into the urine, leaving low blood protein, high cholesterol and swelling. Among supplements, vitamin D and omega-3 fatty acids have the most research behind them, and the evidence for each is moderate. One small study of 23 people found spirulina improved blood glucose, but evidence for most other options is limited.
- Best evidence:
Pancreatitis
Pancreatitis is inflammation of the pancreas, the organ that makes digestive enzymes and insulin; in acute cases, those enzymes switch on inside the gland and digest it. The evidence is strongest for pancreatic enzymes and vitamin D, which address poor digestion and low fat-soluble vitamins, while secretin testing assessed pancreatic function with roughly 79 to 92 percent accuracy. Curcumin raised antioxidant enzymes in only 20 people, so that finding is early.
- Best evidence:
Periodontitis
Periodontitis is a serious gum infection in which bacteria and the body's own inflammatory response damage the soft tissue and bone that hold teeth in place, and it can lead to tooth loss. Among supplements, vitamin D and coenzyme Q10 have the strongest support, with the evidence rated moderate in hundreds of participants. Resveratrol trials found blood glucose improved, but that is a different outcome from gum health, and the evidence there is limited.
- Best evidence:
Short Bowel Syndrome (SBS)
Short bowel syndrome means too little working small intestine remains, so the body struggles to absorb food, fluid and nutrients. Evidence is strongest for teduglutide, and reviews of 16 studies found many people needed less intravenous nutrition or fluid support, with 74% reaching at least a fifth less after two years. Colostrum's evidence is limited: one small trial of eight people found improved muscle mass.
- Best evidence:
Thyroid Health
The thyroid is a small gland in the neck that makes hormones controlling metabolism, energy and growth. Iodine and selenium have the strongest evidence, since iodine is built into thyroid hormones and selenium helps convert T4 into active T3, and in one small trial of healthy men, blood T3 went down with iodide supplements. That finding rests on just 32 men, so the evidence is limited and may not apply to people with thyroid problems.
- Best evidence:
Acute Mountain Sickness
Acute mountain sickness is the headache, nausea, fatigue and poor sleep that can follow climbing to high altitude faster than the body can adjust to thinner air. Ginkgo biloba has the most support, and across six trials with over 800 people, symptoms eased, with moderate evidence. Rhodiola's active compound has mostly been studied in the lab, and gradual ascent remains the best-established approach.
- Best evidence:
Agoraphobia
Agoraphobia is an anxiety disorder in which people fear and avoid places like public transport, crowds, or being outside alone, because escape or help might feel out of reach if panic strikes. Among supplements, inositol has the most research behind it, and small trials found anxiety symptoms eased in people with panic-related fears. Those studies were tiny, about 21 people across three studies, so the evidence is limited and firm conclusions aren't possible yet.
- Best evidence:
Alcoholic Hepatitis
Alcoholic hepatitis is severe liver inflammation caused by heavy drinking, which can bring jaundice, belly pain and fever. Among supplements, research is thin: Japanese raisin tree extract lowered liver enzymes in small trials, though the evidence is limited, while resveratrol showed no clear difference in bilirubin. Those enzyme findings came mostly from animal studies and people with fatty liver or hangovers, not alcoholic hepatitis itself.
- Best evidence:
Arsenic Poisoning
Arsenic poisoning happens when inorganic arsenic, often from contaminated drinking water, builds up in the body and damages cells, causing skin lesions and raising the risk of cancer, heart disease, and diabetes. The evidence is strongest for charcoal, which limited how much arsenic the gut absorbed after acute poisoning, and moderate for NAC and selenium. Charcoal only applies to sudden exposure, and the evidence for antioxidants is thinner: curcumin raised antioxidant enzyme levels, but the evidence is limited.
- Best evidence:
Autoimmune Health
Autoimmune conditions arise when the immune system, which normally defends against germs, mistakenly attacks the body's own tissues and causes ongoing inflammation. Among supplements, yeast mannan has the most research behind it, and animal studies in fish, mice and poultry found stronger immune responses; Dang Shen and Dendrobium showed similar effects in lab work. Still, this evidence is limited, nearly all of it comes from animals or cell studies, and no human trials have confirmed it.
- Best evidence:
Basketball performance
Basketball is a fast, stop-start sport that asks the body for repeated sprints, jumps and quick changes of direction across four quarters. Among supplements, the evidence is strongest for creatine and caffeine, which research has linked to better power, sprint performance and alertness, and caffeine has a meta-analysis behind it. The other options have moderate evidence at best, and a tiny ten-person study of alanylglutamine found less fatigue.
- Best evidence:
Bone Cancer
Bone cancer is abnormal cells growing in bone, either cancers that start there, like osteosarcoma and Ewing sarcoma, or cancers from the breast, prostate or lung that spread to it. The strongest evidence is for denosumab, and studies found it reduced skeletal-related events in people with bone metastases from solid tumors. That finding applies to spread-to-bone disease rather than every type, and evidence for vitamin D and calcium is only moderate.
- Best evidence:
Chronic Low Back Pain
Chronic low back pain is back pain lasting more than 12 weeks, often linked to strained muscles, worn discs or arthritic joints, though sometimes no structural cause turns up. Among supplements, devil's claw has the strongest evidence, with a review of trials finding short-term pain improved versus placebo and less need for rescue pain medication. The studies were small and short, and agmatine eased nerve-related back pain in only one trial of 61 people.
- Best evidence:
Dental Health
Dental health is the condition of your teeth, gums, and the community of microbes in your mouth, and it is linked to more than cavities, including heart disease and diabetes. Among supplements, magnolia bark extract, studied in a sugar-free chewing gum, has trial findings: measures of dental health improved in a randomized trial. The evidence is limited, though, since that result comes from a single trial of 120 people.
- Best evidence:
Dermatitis
Dermatitis, or eczema, is inflamed, red, itchy, dry skin, and the common atopic type often runs in families with allergies and asthma. Probiotics and vitamin D have the most research behind them, rated moderate, and hyaluronic acid improved skin severity in people having radiotherapy. Evidence for evening primrose oil, omega-3s and zinc is limited, and the hyaluronic acid result came from one analysis of 104 people, not everyday eczema.
- Best evidence:
Diabetic Foot Ulcers
Diabetic complications commonly include decreased sensation in the feet and impaired wound healing. Damage to the feet often goes unnoticed and can cause ulcerations.
- Best evidence:
Gastroesophageal Reflux Disease (GERD)
GERD happens when the valve at the bottom of the esophagus relaxes at the wrong times, letting stomach acid wash back up and cause heartburn and regurgitation. Melatonin has the most research, and a trial of 60 people found gastrin levels changed, though which way is unclear; one astaxanthin study found no clear difference in inflammation. Both studies were small, so the evidence remains limited.
- Best evidence:
General Oral Health
Oral health means keeping your teeth, gums, and the hundreds of bacterial species in your mouth in balance, which matters for more than cavities. The evidence is strongest for Triphala mouthwash, which trials found reduced plaque and gum inflammation about as well as chlorhexidine, a medicated rinse, while aloe vera showed a small improvement in dental health measures. That aloe vera finding came from one small study of 141 people, so it is early.
- Best evidence:
Inflammation
Inflammation is the body's defense response, in which immune cells release chemical signals to deal with injury or infection, though it can linger and cause harm when it stays switched on. Among supplements, black seed oil and urolithin A have the strongest evidence, and trials found lower levels of C-reactive protein, a common blood marker of inflammation. Those studies were fairly small, and other options such as luteolin rest mostly on animal or lab work.
- Best evidence:
Mental Health
Mental health describes how we think, feel and cope, shaped by brain chemistry, stress hormones and life circumstances. Selank and magnolia bark have the most supporting research: across six studies, anxiety symptoms went down with Selank, and in one four-week trial a magnolia bark product eased stress and improved mood. The evidence is moderate, though the magnolia trial was small, and luteolin's promise comes mostly from animal work.
- Best evidence:
Renal Anemia
Renal anemia happens when damaged kidneys make too little erythropoietin, the hormone that tells bone marrow to build red blood cells, leaving people with low hemoglobin, fatigue and breathlessness. Iron has the strongest evidence among supplements, and in dialysis trials a once-monthly drug, peginesatide, kept hemoglobin as steady as epoetin over a year. The supplement research is thinner: a single study of 14 people found L-carnitine made no clear difference to hematocrit.
- Best evidence:
Somatization Disorder
Somatic symptom disorder, once called somatization disorder, is a condition where real physical symptoms such as pain, fatigue, or gut trouble come with worry and distress out of proportion to them. Lavender has drawn the most interest among supplements, and small studies found anxiety symptoms eased, though the evidence is limited. Those studies were small, 47 people in all, and looked at lavender scent in dental patients rather than this condition.
- Best evidence:
Wound Healing
Wound healing is the body's repair process after skin is cut or damaged, in which clotting, inflammation, new tissue growth and collagen building work in sequence to close the gap. Among supplements, the evidence is strongest for vitamin B5, where wounds closed faster in about 500 participants, and moderate for copper and manganese, which also raised wound closure rates. The copper and manganese findings came from about 160 people, and the studies were only moderate in size, so the results are encouraging but not settled.
- Best evidence:
Diabetes
Diabetes is a long-term condition in which the body makes too little insulin or can't respond to it well, so sugar lingers in the blood. Bitter melon has the most research among supplements, and trials found it was well tolerated, with side effects similar to placebo, mostly stomach upset and headache. TB-500 improved blood sugar and insulin resistance in diabetic mice, but that is animal work only, so the evidence is very limited.
- Best evidence:
Aging
Aging is the buildup of cell damage over time, as energy production slows and muscle and skin repair less well. The evidence is strongest, though still limited, for essential amino acids, which trials found may have modestly improved physical function in older adults, and for Terminalia chebula, which reduced facial wrinkles in women. The wrinkle result came from one small trial, and amino acid gains were small, mostly in older adults with health conditions.
- Best evidence:
Barth Syndrome
Barth syndrome is a rare genetic condition in which a faulty TAFAZZIN gene disrupts cardiolipin, a fat mitochondria need to make energy, leaving muscles and the heart weak. Elamipretide has the strongest evidence, and in a long-term follow-up people walked about 96 meters farther in six minutes than at the start. That follow-up was open-label with only 10 people, and oleoylethanolamide has very limited support, from lab-grown cells alone.
- Best evidence:
Boxing Performance
Boxing performance rests on explosive punching power, quick hands and reactions, and the stamina to keep working through twelve three-minute rounds. The evidence is strongest for creatine and caffeine, both studied for power output and repeated hard efforts, with caffeine also looked at for reaction time. Blood acidity went down in a few studies of sodium bicarbonate, but those were tiny, so that evidence is limited.
- Best evidence:
Breast Pain
Breast pain, or mastalgia, is very common, either following the menstrual cycle or not, and it is rarely a sign of breast cancer. Evening primrose oil and vitamin E are the supplements people turn to most, but little research on them has been reviewed here so far. Vitex, vitamin B6 and magnesium get attention too, though their evidence is limited to moderate.
- Best evidence:
Carpal Tunnel Syndrome
Carpal tunnel syndrome happens when the median nerve is squeezed as it passes through the wrist, causing numbness, tingling and weakness in the thumb, index and middle fingers. Vitamin B6 and alpha-lipoic acid are the most studied options, and the evidence for each is moderate. Still, the only trial result available was small: 63 people used astaxanthin alongside splinting, and their HDL cholesterol improved.
- Best evidence:
Cataracts
A cataract is a clouding of the eye's natural lens that brings blurry vision and glare and can cause vision loss. Lutein and zeaxanthin, plant pigments that gather in the eye, have the strongest evidence, rated moderate: in a study of about 1,800 women, higher levels in the diet and blood went along with less nuclear cataract. That evidence is mostly observational, so it shows an association, not proof.
- Best evidence:
Diabetic Microangiopathy
Diabetic microangiopathy is damage to the body's smallest blood vessels caused by diabetes, and it underlies diabetic eye and kidney disease while contributing to nerve damage. Among supplements, the evidence is moderate for gotu kola, where trials found blood flow went up, and limited for curcumin, where one study found the same. Both studies were small, with about 100 and 25 people, so the picture is still early.
- Best evidence:
Epilepsy
Epilepsy is a neurological condition in which bursts of abnormal electrical activity in the brain cause recurrent seizures, and it ranges from mild to severe. Among supplements, the evidence is strongest for cannabidiol (CBD), and large trials in drug-resistant epilepsy, including Lennox-Gastaut syndrome, found people had fewer seizures. Vitamin D has moderate support, but the CBD findings come from specific hard-to-control forms of epilepsy, and most other supplements have only limited research behind them.
- Best evidence:
Gout
Gout is a form of inflammatory arthritis in which high blood uric acid forms crystals in joints, causing sudden, severe pain, swelling, and redness. Vitamin C and tart cherry have the most support, with moderate evidence, yet a trial of tart cherry in 50 people found no clear difference in gout symptoms. That was a single small study, so the picture is still unsettled.
- Best evidence:
Hair Loss
Hair loss, or alopecia, is thinning or shedding of scalp hair, with causes ranging from genetics to nutrient shortfalls to medical conditions. Among supplements, the evidence is moderate for biotin, iron and zinc, all linked to hair loss when the body is low in them. Evidence is thinner elsewhere: two small trials of probiotics, with 219 people, found no clear difference in hair regrowth.
- Best evidence:
HIV Infection
HIV is a virus that infects the immune system's CD4 cells, gradually weakening the body's defenses against other infections. Enfuvirtide has the strongest evidence, and a phase III trial found it lowered viral load more than an optimized background regimen alone at 24 weeks in people who had already tried other HIV medicines. Those results mostly apply to people with that history and to 24 weeks, so they say less about longer-term outcomes.
- Best evidence:
Lupus Nephritis
Lupus nephritis is kidney inflammation caused by lupus, in which the immune system attacks the tiny filters in the kidneys, letting protein leak into the urine. The strongest evidence is for voclosporin, a prescription medicine, and a large placebo-controlled trial found more people reached a complete kidney response when it was added to standard treatment (about 41% versus 23%). No true supplements have gathered enough trial evidence yet, so their role is still unclear.
- Best evidence:
Microangiopathy
Microangiopathy is disease of the body's smallest blood vessels, most often in diabetes, where long-term high blood sugar, oxidative stress and inflammation damage vessel walls and reduce blood flow to the eyes, kidneys and nerves. Among supplements, a ginkgo study found better microcirculation, and gotu kola research found blood flow went up. The evidence for both is limited, though: the ginkgo study involved just 32 elderly patients, and the gotu kola work was small too.
- Best evidence:
Mucositis
Oral mucositis is painful inflammation and sores in the mouth lining, which arise because its fast-dividing cells are easily damaged by chemotherapy and head and neck radiation. Among supplements, the evidence is strongest for curcumin, and trials found mouth symptoms improved. That rests on just two studies with 272 people and a moderate-sized effect, so more research would help firm it up.
- Best evidence:
Organic Brain Syndrome
Organic brain syndrome is a broad term for impaired thinking and memory that stems from a physical cause affecting the brain, such as disease or injury. Vitamin B12 has the strongest evidence rating, since low levels are a common cause of reversible cognitive impairment, and omega-3 fatty acids rate moderate. In four small oxiracetam trials, cognitive decline eased. Those studies included only about 60 people, so that evidence is limited.
- Best evidence:
Percutaneous Coronary Intervention
Percutaneous coronary intervention is a procedure that uses a catheter and usually a stent to open a narrowed heart artery and restore blood flow. The evidence is strongest for bivalirudin, which brought less major bleeding than heparin plus another clot-blocking drug, and eptifibatide, after which fewer people had a death or heart attack following stenting. Eptifibatide's findings came from one trial of about 2,000 people followed for six months.
- Best evidence:
Postural Syncope
Postural syncope is fainting or near-fainting when blood pressure drops on standing, so too little blood reaches the brain and causes dizziness or falls. Among supplements, sodium and electrolytes have the strongest, moderate evidence, with symptoms easing in studies of about 800 people, possibly because they expand blood volume. Evidence for vitamin B12 and others is limited, and one small study of 29 people found mixed blood pressure effects with cannabis.
- Best evidence:
Premenstrual Dysphoric Disorder (PMDD)
Premenstrual dysphoric disorder is a severe form of premenstrual syndrome in which the body seems unusually sensitive to normal hormone shifts, bringing mood swings, irritability and physical discomfort before a period. The evidence is strongest for calcium, where trials found mood and physical symptoms eased, with vitamin B6 and vitex backed by moderate evidence. For depression symptoms specifically, though, inositol showed no clear difference across five small studies.
- Best evidence:
Preterm Labor
Preterm labor is when regular contractions begin to open the cervix before 37 weeks of pregnancy, as the body starts preparing for birth too early. The evidence is strongest for atosiban, and a placebo-controlled trial found more women had not yet delivered after 24 hours, 48 hours and 7 days. Those gains were seen from 28 weeks onward, while it was less effective earlier in pregnancy.
- Best evidence:
Secondary Hyperparathyroidism
Secondary hyperparathyroidism happens when the parathyroid glands make too much parathyroid hormone (PTH), usually because failing kidneys leave calcium low and phosphate high. Evidence is strongest for etelcalcetide, a calcimimetic medicine: trials found about three in four people had PTH fall by over 30%, versus one in ten on placebo, and it beat cinacalcet head to head. Those results came mainly from people on hemodialysis, so they may not apply to everyone with the condition.
- Best evidence:
Tennis Performance
Tennis is an intermittent sport that blends power, agility, endurance, and focus, with matches lasting anywhere from one to five-plus hours. Among supplements, the evidence is strongest for caffeine, electrolytes, and whey protein, which are linked to alertness and endurance, hydration in long or hot matches, and muscle recovery. Creatine has moderate evidence, while citrulline has very limited research, with one small study of 21 people finding no clear difference in anaerobic capacity.
- Best evidence:
Tinnitus
Tinnitus is the perception of sound with no outside source, often described as ringing, buzzing or hissing, and it affects roughly 10 to 15 percent of adults. Melatonin has the most support among supplements, and the evidence is moderate: in a small group of people, sleep quality improved. Ginkgo, zinc, vitamin B12 and magnesium have been studied too, but the evidence for each is limited, and the melatonin findings apply mostly to people whose tinnitus disturbs their sleep.
- Best evidence:
Tourette Syndrome
Tourette syndrome is a neurodevelopmental condition in which the brain's movement circuits produce repetitive, involuntary movements and sounds called tics, usually beginning in childhood and often easing in adulthood. Magnesium and omega-3 fatty acids have drawn the most interest among supplements, and some research pointed to fewer tics with magnesium, though the evidence for both is limited. Those studies included about 200 people or fewer, and cannabis research found no clear difference in ADHD symptoms.
- Best evidence:
Vitiligo
Vitiligo is an autoimmune condition in which the immune system attacks melanocytes, the cells that make skin pigment, causing white patches. Afamelanotide has the strongest evidence, which is moderate, and a trial found more repigmentation when it was added to narrowband UVB light than with the light alone. Vitamin D and B12 with folic acid have only limited evidence, and a small bakuchi pilot was inconclusive.
- Best evidence:
Achondroplasia
Achondroplasia is a genetic condition in which a change in the FGFR3 gene overactivates a signal that slows cartilage turning into bone, leading to shorter limbs. Vosoritide, a medicine rather than a supplement, has the strongest evidence: in a trial of 121 children, it increased yearly growth speed compared with placebo. That trial ran 52 weeks in ages 5 to 14, so results mostly apply to children in that range.
- Best evidence:
Bacterial Vaginosis (BV)
Bacterial vaginosis is a common condition in which protective Lactobacillus bacteria in the vagina decline and others, like Gardnerella, overgrow, often causing thin gray discharge and a fishy odor. Lactobacillus probiotics have the strongest evidence, with moderate support for vitamin D and vaginal boric acid, and symptoms improved in one calendula trial. That trial had only 80 women, and large trials of L. acidophilus alone are limited.
- Best evidence:
Cachexia
Cachexia is severe, unintended weight loss with muscle wasting, seen in cancer, heart failure, COPD and kidney disease, where inflammation drives muscle breakdown even when eating is adequate. The evidence is strongest for EPA omega-3s, protein, and oral nutritional supplements, which target inflammation, muscle building and calorie intake. Valine has very limited support: a small bed-rest study found less protein wasting, but the credit went to the amino acid mix.
- Best evidence:
Canker Sores
Canker sores are painful, shallow mouth ulcers that are not contagious and often follow injury, stress, or low nutrient levels. The evidence is moderate for vitamin B12, iron, and folic acid, and research linked correcting a shortfall to fewer recurrences. Aloe vera gel eased symptoms in two small studies, but most other supplements have limited evidence, and benefits likely apply mainly to people who are low.
- Best evidence:
Chronic Cerebrovascular Insufficiency
Chronic cerebrovascular insufficiency is a long-term reduction in blood flow to the brain, usually because hardened arteries narrow the vessels that supply it, which can cause dizziness, memory problems and trouble concentrating. Among supplements, vinpocetine has the clearest finding: a trial found a small improvement in cognitive function in people with vascular dementia. That came from just one small study, so the evidence is limited.
- Best evidence:
Constipation-Predominant Irritable Bowel Syndrome (IBS-C)
IBS-C is a long-term gut disorder in which recurring abdominal pain comes with hard, infrequent stools, shaped by close signaling between gut and brain. Psyllium fiber and peppermint oil have strong evidence behind them, while in large trials linaclotide and plecanatide helped about 30 to 34 percent of people reach pain and bowel goals, versus 14 to 21 percent on placebo. Those results come from drugs, so they don't show what supplements do.
- Best evidence:
Dry Eye
Dry eye happens when your eyes make too few tears or the tears evaporate too quickly, leaving them stinging, gritty and tired. Hyaluronic acid and trehalose eye drops have the strongest support, and studies found dry eye symptoms improved with both. Still, the trehalose trials enrolled only about 70 people, and oral options such as sea buckthorn oil have limited evidence from a single small study.
- Best evidence:
Dysthymia
Dysthymia, now called persistent depressive disorder, is a chronic, milder depression in which low mood and fatigue last at least two years, linked to changes in brain mood circuits. Omega-3 fatty acids have the strongest evidence among supplements, drawn from research on depression, with vitamin D next at moderate. Most of that work covered depression broadly rather than dysthymia itself, and the one dysthymia-specific finding was small: anxiety symptoms eased with L-carnitine.
- Best evidence:
Gingivitis
Gingivitis is inflammation of the gums, usually set off by plaque building up along the gumline, and it is the earliest stage of gum disease. Coenzyme Q10 and vitamin C have the strongest evidence, rated moderate, while neem mouthwash lowered plaque scores about as well as chlorhexidine in some studies. Neem research was small, though, and a single calendula trial found no clear difference in dental health measures.
- Best evidence:
Hepatorenal Syndrome
Hepatorenal syndrome is a serious loss of kidney function in advanced liver disease, driven by altered blood flow to the kidneys rather than direct kidney damage. Terlipressin, a prescription drug, has the strongest evidence: in a 300-person phase 3 trial, the syndrome resolved in 32% of people on it versus 17% on placebo. Most people on the drug still did not recover in that trial.
- Best evidence:
Hypogonadotropic Hypogonadism
Hypogonadotropic hypogonadism is a condition in which the pituitary gland releases too little LH and FSH, so the testes or ovaries make too little sex hormone. Research has focused on gonadorelin, a diagnostic test rather than a supplement, and the evidence is strong that it shows how the pituitary responds by measuring LH and FSH. Before puberty it could not separate this condition from constitutionally delayed puberty, but afterward it was useful.
- Best evidence:
Idiopathic Oligoasthenoteratozoospermia (IOAT)
IOAT is a defect in the production of fertilizing sperm (spermatogenesis) for which the cause is unknown. IOAT is a condition of male infertility.
- Best evidence:
Immune Thrombocytopenia
Immune thrombocytopenia is a condition in which the immune system mistakenly attacks platelets, the cell fragments that help blood clot, so counts fall and bruising and bleeding become likelier. The strongest evidence is for romiplostim, a medicine, and trials found lasting platelet responses in 38% of adults without a spleen and 52% of children, versus 0% and 10% on placebo. Those results come from specific groups, so they may not apply to everyone.
- Best evidence:
Macular Degeneration
Macular degeneration is an eye condition in which the central part of the retina, the macula, gradually wears down, blurring the sharp vision needed for reading and recognizing faces. Saffron is the main supplement studied, and its plant compounds crocin and safranal may protect the light-sensing cells of the retina. Even so, the evidence is limited, and a small trial of 60 people found no clear difference in macular thickness, so it remains unclear how much saffron helps.
- Best evidence:
Marijuana Withdrawal
Cannabis withdrawal is a recognized condition that follows when regular, heavy users stop or cut back, as a brain used to cannabis readjusts, causing discomfort that can lead to relapse. N-acetyl cysteine has the most support, with moderate evidence, since it acts on glutamate and was studied specifically in cannabis use disorder, while omega-3s have limited evidence. Other supplements have limited evidence too, and one cognition finding, in 24 people, was mixed.
- Best evidence:
McArdle Disease
McArdle disease is a rare inherited muscle disorder in which the body lacks myophosphorylase, an enzyme that releases glucose from stored glycogen, so working muscles struggle to get enough fuel. Creatine is one of the main supplements people look at, and trials found mixed results for exercise tolerance. That rests on just three small studies with 28 people in total, so the evidence is limited and no clear benefit has been shown.
- Best evidence:
Morning Sickness
Morning sickness is the nausea, sometimes with vomiting, that many people feel in early pregnancy, tied to rising hormones like hCG and estrogen that affect the digestive system. Ginger has the best evidence among supplements, and across nine studies with 216 participants, nausea symptoms improved. Those studies were only moderate in size, so the picture is encouraging but rests on a fairly small group of people.
- Best evidence:
Musculoskeletal Health
Musculoskeletal health covers the bones, muscles, tendons and joints that support the body and let it move. Two peptides, BPC-157 and TB-500, have the most research, and studies found better tendon recovery with the first and improved tissue repair with the second, though the evidence is limited for both. Much of it was in animals and cells, and the TB-500 work centered on the heart, so its relevance to people is unclear.
- Best evidence:
Neuropathic Pain
Neuropathic pain comes from damage or disease in the nervous system, which sends faulty signals that feel burning, shooting, stabbing, or like electric shocks. Among supplements, alpha-lipoic acid, especially for diabetic nerve pain, and acetyl-L-carnitine have the strongest support, rated moderate. In four small cannabis studies, people used less pain medication, though that evidence is limited. Those studies enrolled just 34 people in total.
- Best evidence:
Opioid-Refractory Pain
Opioid-refractory pain is long-lasting pain that opioid medicines don't relieve well enough, or that opioids can't be used for because of side effects or risks. Palmitoylethanolamide and alpha-lipoic acid have the strongest support, with moderate evidence, and in four small cannabis studies people used less pain medication. Even so, the cannabis research was small and the evidence limited, and the other supplements looked at, such as magnesium and curcumin, have limited evidence.
- Best evidence:
Oral Lichen Planus
Oral lichen planus is a long-lasting inflammatory condition of the lining of the mouth, thought to be autoimmune, in which the body's immune cells attack the tissue and cause white lacy patches, red areas, or painful sores. Curcumin and aloe vera have the most support, though the evidence is only moderate. In one small study of 20 people, curcumin was linked to a drop in the inflammation marker CRP. That is a lab measure rather than a symptom, and the other supplements studied have limited or very limited evidence.
- Best evidence:
Peripheral Arterial Occlusive Disease
Peripheral arterial occlusive disease happens when fatty deposits narrow the arteries that carry blood to the legs, reducing blood flow and causing pain when walking. Omega-3 fatty acids and L-arginine have the most support, each with moderate evidence overall, and in one trial of 39 people, blood flow went up with arginine. That result comes from one small study, so the evidence there is limited.
- Best evidence:
Photodermatoses
Photodermatoses are skin conditions in which light, usually sunlight, triggers or worsens a reaction, from common polymorphous light eruption to rare inherited disorders. The evidence is strongest for afamelanotide, with trials in erythropoietic protoporphyria finding people gained much more pain-free time in sunlight, and for nicotinamide, which helps cells repair UV damage. Beta-carotene and fern extract have moderate support, but the afamelanotide results apply to that one rare condition.
- Best evidence:
Primary Biliary Cholangitis
Primary biliary cholangitis is an autoimmune condition in which the immune system attacks the small bile ducts in the liver, so bile builds up and damages the liver. Vitamin D and calcium have the strongest evidence, mainly for bone health, since fat malabsorption can leave levels low and osteoporosis risk is high. For bile flow, one very small study of 12 people found cholestasis went down with TUDCA, but that evidence is limited.
- Best evidence:
Sailing Performance
Sailing performance is the blend of strength, endurance, mental focus and tactical decision-making that racing demands, with needs shifting by boat class and race length. The evidence is strongest for caffeine, electrolytes and creatine, studied for alertness, sweat losses and power during hiking. Little of it is sailing-specific, though; one small study of 12 people found branched-chain amino acids eased fatigue, but that evidence is limited.
- Best evidence:
Septic Shock
Septic shock is a life-threatening drop in blood pressure after a severe infection, when widened, leaky blood vessels leave organs short of blood flow. Angiotensin II, a hormone that tightens blood vessels, has strong evidence behind it: in one trial, 70% of people reached a target blood pressure within three hours, versus 23% on placebo. Those participants had shock that resisted standard drugs, so results mostly apply to that group.
- Best evidence:
Severe Hypoglycemia
Severe hypoglycemia is a dangerously low blood sugar episode in which the brain runs short of fuel, causing confusion, seizures or fainting. The hormone glucagon, which tells the liver to release stored sugar, has the strongest evidence: across 16 studies, nearly everyone's glucose recovered within 30 minutes, typically in 10 to 13 minutes. Injected and nasal forms worked about equally well, though the research comes mostly from people with diabetes.
- Best evidence:
Skin Cancer
Skin cancer starts when skin cells, often damaged by sunlight, grow out of control; the main types are basal cell, squamous cell, and melanoma. The evidence is strongest for nicotinamide, a form of vitamin B3, in people at high risk of new skin cancers, though studies found no clear difference for melanoma. Large beta-carotene trials found no reduction in non-melanoma risk, and evidence for other supplements is limited.
- Best evidence:
Social Anxiety Disorder
Social anxiety disorder is an intense fear of being judged or embarrassed in social situations, bringing blushing, sweating and a racing heart. Lavender (Silexan), L-theanine and ashwagandha have the best evidence, rated moderate, with studies finding lower anxiety or stress symptoms. Some of that work looked at general stress and anxiety rather than social anxiety itself, so how well it applies here is unclear.
- Best evidence:
Tension Headache
Tension headache is the most common kind of headache, a dull, aching pain often felt like a tight band around the head, linked to stress, poor posture and tense neck muscles. Among supplements, peppermint oil applied to the skin has the most support, and trials found headaches improved, about as well as with acetaminophen. Those trials were small, though, so the evidence is moderate at best.
- Best evidence:
Trichotillomania (Hair Pulling)
Trichotillomania is a hair-pulling disorder in which people feel compelled to pull hair from the scalp, eyebrows or eyelashes, and it is grouped with obsessive-compulsive related conditions. The evidence is strongest for N-acetyl cysteine, a glutamate modulator tested in a randomized trial for hair pulling, while inositol has only limited evidence. Still, the leading option showed no clear difference for anxiety in one small group of 50 people, and the other supplements have limited research.
- Best evidence:
Urinary Incontinence
Urinary incontinence is the involuntary leakage of urine, caused either by a weak pelvic floor that gives way under pressure or by a bladder that signals a sudden, hard-to-control urge. Among supplements, octopamine has the most trial support, and three small trials found signs of stress incontinence in women eased. Those studies included only 97 people in total, so the evidence is moderate at best, and pelvic floor exercises remain the main approach.
- Best evidence:
Vasodilatory Shock
Vasodilatory shock is a life-threatening state in which blood vessels widen so much that blood pressure falls and organs receive too little blood. The evidence is strong for vasopressin: in a randomized trial, average blood pressure was higher at 24 hours when it was added to norepinephrine than with norepinephrine alone. That finding concerns blood pressure support in critically ill people who were already receiving standard care.
- Best evidence:
Vitamin B12 Deficiency
Vitamin B12 deficiency happens when the body lacks enough of the vitamin it uses to keep nerves working, build DNA, and form red blood cells. The evidence is strongest for vitamin B12 itself and for folate, which works alongside it in the body. Even so, trials looking at cognition found no clear difference, and that evidence is very limited, though iron and B-complex vitamins have moderate support.
- Best evidence:
Acute Liver Failure
Acute liver failure is an emergency in which the liver quickly loses function in someone without prior liver disease, causing confusion, bleeding problems, and sometimes multi-organ failure. N-acetylcysteine has the strongest support, as a hospital standard after acetaminophen overdose, but a pooled analysis of trials found no clear difference in survival when it was used for other causes. That finding rests on very limited evidence, and support for other supplements is moderate at best.
- Best evidence:
Acute Viral Hepatitis
Acute viral hepatitis is inflammation of the liver caused by hepatitis viruses A, B, C, D, or E, bringing fatigue, nausea, dark urine, and yellowing of the skin and eyes. Milk thistle and N-acetyl cysteine have the strongest evidence, rated moderate, and in a small Kutki study bilirubin, the pigment behind jaundice, went down. That Kutki study involved just 33 people, and oxymatrine research for hepatitis B used injections, not oral products.
- Best evidence:
Atrial Fibrillation
Atrial fibrillation is a heart rhythm disorder in which the upper chambers beat irregularly and often fast, letting blood pool and sometimes form clots. Magnesium and omega-3 fatty acids have the most support among supplements, both rated moderate, though research on magnesium in about 1,550 people found no clear difference in deaths from any cause. Evidence for others, such as coenzyme Q10 and taurine, is limited.
- Best evidence:
Autoimmune Disease
Autoimmune disease occurs when the immune system mistakenly attacks the body's own tissues, causing inflammation in places like the joints, thyroid, gut or nerves. Vitamin D and omega-3 fatty acids have the strongest evidence among supplements for calming immune activity, while a review found thunder god vine strongly suppressed immune function in autoimmune conditions. That effect carried serious side-effect risks, and options like idebenone and punarnava rest mostly on animal or lab work.
- Best evidence:
Autonomic Dysfunction
Autonomic dysfunction, or dysautonomia, is a problem with the nervous system that controls automatic functions like heart rate and blood pressure, often bringing lightheadedness on standing. Sodium and electrolytes have the strongest evidence, rated moderate, since extra sodium expands blood volume. Matured hop extract raised heart rate variability in one small trial of 34 healthy older adults, but that evidence is very limited and may not apply to people with dysautonomia.
- Best evidence:
Biliary Dyskinesia
Biliary dyskinesia is a condition in which the gallbladder does not empty bile well, even without gallstones, which can cause pain in the upper abdomen after meals. Sincalide, a gallbladder-stimulating agent used in scans, has the strongest evidence: 12 studies helped define normal emptying, with readings below roughly 35 to 40 percent pointing to poor function. Those findings describe how the problem is measured, not whether any supplement changes symptoms.
- Best evidence:
Burning Mouth Syndrome (BMS)
Burning mouth syndrome is a long-lasting condition in which the tongue, lips, or palate feel burning, scalding, or tingling even though the mouth looks normal, and it mostly affects postmenopausal women. Among supplements, alpha-lipoic acid and vitamin B12 have the most research behind them, and the evidence for each is moderate. Other options rest on limited evidence, such as one small cannabis study of 17 people where symptoms eased.
- Best evidence:
Central Hypothyroidism
Central hypothyroidism is an underactive thyroid caused by a signaling problem in the pituitary or hypothalamus, so the thyroid gets too little prompting to make hormone. Protirelin, a lab-made version of the hormone TRH, has the strongest evidence, and research found its test separated pituitary causes (a blunted response) from hypothalamic ones (a delayed or exaggerated response). It works as a diagnostic aid, proving most valuable in people with known pituitary disease.
- Best evidence:
Chronic Kidney Disease-Associated Pruritus
Chronic kidney disease-associated pruritus is persistent itching in people with advanced kidney disease, thought to stem from an imbalance in the body's opioid signaling along with inflammation. The evidence is strongest for difelikefalin: in trials, 51% of people had a meaningful drop in itch intensity versus 28% on placebo, lasting up to 64 weeks. Most of that research was in people on hemodialysis, and about half did not reach that level of relief.
- Best evidence:
Chronic Nonspecific Knee Pain
Chronic nonspecific knee pain is characterized as long-term pain, stiffness, and decreased range of motion in the knee joint triggered by an unknown cause.
- Best evidence:
Cocaine Abuse
Cocaine use disorder is compulsive cocaine use despite harm, as repeated dopamine surges leave the brain with fewer dopamine receptors, fueling tolerance and craving. N-acetyl cysteine has the strongest evidence among supplements, with omega-3 fatty acids moderate, and in one placebo-controlled trial of 73 cocaine-dependent volunteers, citicoline improved addiction symptoms. That citicoline evidence is limited, resting on a single small study, so it is an early signal rather than a firm answer.
- Best evidence:
Cold Sores
Cold sores are blisters on or around the lips, caused by herpes simplex virus type 1, which lingers in nerve cells after childhood infection and can flare with stress, sun, or illness. L-lysine, topical honey, and zinc have the strongest evidence among supplements, rated moderate, but the one lysine study found no clear difference in how often sores came back. That trial was tiny, just 26 people, so it says little either way.
- Best evidence:
Cushing's Disease
Cushing's disease is a hormone condition in which a small pituitary tumor makes too much ACTH, driving the adrenal glands to overproduce cortisol. In a phase III trial of pasireotide, a medicine with strong evidence, 25% reached normal urinary cortisol by six months and 76% saw levels fall. Cortisol dropped within two months and stayed lower for up to 24 months, but roughly three in four people still did not reach normal levels.
- Best evidence:
Cushing's Syndrome
Cushing's syndrome is what happens when the body has too much cortisol, the main stress hormone, often from a pituitary tumor or steroid medicines. The strongest evidence is for a diagnostic test using ovine corticorelin: across 15 studies it identified Cushing's disease with about 86 to 93 percent sensitivity and beat the dexamethasone suppression test for accuracy. That work is about finding the cause, not easing symptoms, so it says nothing about supplements.
- Best evidence:
Driving Performance
Driving performance is your ability to stay alert, react quickly and hold attention, and it slips with sleep loss, monotonous roads, long stretches without breaks and the body's natural low points. Caffeine has the strongest evidence, with research pointing to less fatigue and quicker reactions, while L-theanine, which may add calm focus, has moderate support. Other supplements have thinner evidence, and cannabis, tested in 147 people, showed no clear difference in driving caution.
- Best evidence:
Early-Onset Puberty
Early-onset puberty is when puberty starts before age 8 in girls or before age 9 in boys, often because the brain signals sex hormones too early. The strongest evidence is for two prescription medicines, histrelin and nafarelin: trials found histrelin kept luteinizing hormone suppressed for years, and nafarelin brought sex hormones down to prepubertal levels and slowed growth. Vitamin D, omega-3s, probiotics and fiber have only limited evidence.
- Best evidence:
Encephalopathy
Hepatic encephalopathy is a decline in brain function that happens when a damaged liver can't clear ammonia, a gut-made toxin that then reaches the brain and causes confusion and personality changes. The evidence is strongest for probiotics and L-ornithine L-aspartate, which are thought to lower ammonia by changing gut bacteria and aiding its breakdown. Branched-chain amino acids and zinc have moderate evidence, while support for vitamin D and omega-3s is limited.
- Best evidence:
Gastrointestinal Cancer
Gastrointestinal cancers start in digestive organs such as the colon, stomach, pancreas, or liver, often disrupting appetite, eating, and nutrient absorption, with treatment adding nausea and diarrhea. Curcumin and omega-3 fatty acids have the most support, with moderate evidence that they may help people tolerate treatment and keep lean body mass. Trial details are thin here, and any benefit looks aimed at easing treatment's strain rather than changing the cancer.
- Best evidence:
Glucose Metabolism
Glucose metabolism is the way your body turns the sugar in food into energy, with the hormone insulin helping cells pull glucose out of the blood. Manganese has limited evidence, as insulin sensitivity went up in small research covering 200 people. Banana flower has very limited evidence: fasting glucose stayed the same in one human trial, though HbA1c fell in another. Banana flower's animal results looked more promising than its human ones.
- Best evidence:
Head and Neck Cancer
Head and neck cancers arise in the mouth, throat, voice box, sinuses, or salivary glands, and treatment can make eating and swallowing hard. The evidence is strongest for protein supplements, aimed at maintaining muscle mass when swallowing limits intake, and moderate for glutamine, studied for radiation-related mouth sores. Calendula improved mouth-sore symptoms in one small trial of 40 people, but that evidence is limited.
- Best evidence:
Hemorrhoids
Hemorrhoids are swollen blood vessels in and around the rectum and anus that can itch, bleed or hurt. The evidence is strongest for fiber and diosmin, and a pooled analysis of 22 trials found a diosmin-based blend lowered bleeding, pain and swelling after hemorrhoid surgery, with horse chestnut moderate. That blend result mostly applies to people recovering from surgery, and the horse chestnut evidence comes from work on vein problems more broadly.
- Best evidence:
Hepatitis B
Hepatitis B is a viral infection of the liver that can be short-lived or become chronic, lasting more than six months. Among supplements, thymosin alpha-1 has the strongest evidence, and three trials with about 520 people found that liver enzyme (ALT) levels returned to normal more often. Vitamin D and vitamin E have also been studied, but evidence for both is limited so far.
- Best evidence:
Hirsutism
Hirsutism is excess hair growth in women in areas where men typically grow it, like the face, chest and back, usually from extra androgens (male hormones) or heightened sensitivity to them. Spearmint tea and inositol have the most support, both moderate, with spearmint studies finding lower free testosterone and inositol linked to improved blood glucose. The inositol glucose finding came from two small studies, and other supplements have only limited evidence.
- Best evidence:
Joint Pain
Joint pain is aching, stiffness or swelling in a joint, caused by things like cartilage wear in osteoarthritis, immune-driven inflammation in rheumatoid arthritis, injury or gout. Among supplements, the evidence is strongest for omega-3 fatty acids, with moderate support for glucosamine and chondroitin, which have been studied mostly for knee pain. One small ashwagandha study of 60 people found osteoarthritis symptoms improved, but that evidence is limited, and results may vary with the cause.
- Best evidence:
Jumping Performance
Jumping performance depends on lower body power, the ability of muscles to produce force quickly, which matters in basketball, volleyball and track and field. The evidence is strongest for creatine, which is linked to better vertical jumps, and caffeine, which supports muscle power output, while beta-alanine has moderate support. A small ginseng study of 20 people found a muscle-damage marker went down after jump drills, which says little about jump height.
- Best evidence:
Kearns-Sayre Syndrome (KSS)
Kearns-Sayre syndrome is a rare mitochondrial disease caused by large deletions in mitochondrial DNA, affecting eye movement, the retina and the heart's electrical signaling. Coenzyme Q10 and L-carnitine are the most studied supplements, with moderate evidence, but the trials reviewed involved creatine, where creatinine went up and muscle energy metabolism showed no benefit. Those studies were tiny, about 15 people in all, so the evidence for creatine is limited.
- Best evidence:
Lipid Metabolism
Lipid metabolism is the body's handling of fats such as cholesterol and triglycerides, including how they are made, broken down, carried in the blood and stored. Among supplements, vitamin B5 (pantothenic acid) has been looked at, and total cholesterol went down in research involving about 200 people. The evidence is limited, though, and the research is small, so it is too early to say how much weight the finding deserves.
- Best evidence:
Liver Cancer
Hepatocellular carcinoma is the most common primary liver cancer, usually starting in a liver already damaged by long-term disease such as hepatitis or cirrhosis. Among supplements, vitamin K has the clearest research, and studies found cancer deaths were lower, with the evidence rated moderate. Those studies were small, and they looked at cancer mortality only, so they say little about other outcomes.
- Best evidence:
Molybdenum Deficiency
Molybdenum deficiency is a rare condition where the body lacks the trace mineral molybdenum, which enzymes need to break down sulfur-containing amino acids. Molybdenum supplements are the option studied, and in a large group of 250 people, the evidence is strong that blood molybdenum levels went up. That result is about blood levels, though, so it says little about how people felt or whether symptoms changed.
- Best evidence:
Motion Sickness
Motion sickness happens when the brain gets conflicting signals about movement from the eyes, the inner ear, and the body, leading to nausea, dizziness, sweating, and sometimes vomiting. Among supplements, ginger has the strongest support, and a trial in naval cadets found seasickness eased a few hours after ginger, with earlier studies showing similar benefits in induced motion sickness. Even so, the evidence is only moderate, results varied with how sickness was triggered and the ginger preparation, and research on other options such as vitamin B6 or peppermint is limited.
- Best evidence:
Narcolepsy
Narcolepsy is a long-term neurological condition in which the brain struggles to control sleep and wake, causing heavy daytime sleepiness and sudden sleep attacks. Vitamin D and iron get the most attention, since low vitamin D is common in narcolepsy and iron influences dopamine, yet the evidence for both is limited. One very small study of 10 people found attention improved with L-tyrosine, so firm conclusions are not possible yet.
- Best evidence:
Panic Disorder
Panic disorder is a condition of recurrent, unexpected panic attacks, sudden surges of intense fear with a racing heart, shortness of breath and dizziness, often followed by worry about the next one. Among supplements, inositol has the most research behind it, and trials found anxiety symptoms improved, with moderate evidence. Those studies were small, though, covering only 41 people in total, so it is early days.
- Best evidence:
Peripartum Depression
Peripartum depression is depression that arises during pregnancy or after delivery, shaped by big hormonal shifts and disrupted sleep. Among supplements, omega-3 fatty acids from fish oil have been studied most, and trials found depression symptoms eased by a moderate amount. Still, the evidence is very limited: it rests on 14 studies with 444 participants in total, so it says little about who benefits most.
- Best evidence:
Peripheral T-Cell Lymphoma
Peripheral T-cell lymphoma is a group of uncommon cancers in which mature T cells, immune white blood cells, grow out of control in lymph nodes and other tissues. The evidence is strongest for romidepsin, a drug, and trials in people whose lymphoma had returned or resisted earlier therapy found about a quarter to nearly 40 percent responded, across major subtypes. Those studies were moderate in size, and most people did not respond.
- Best evidence:
Pitting Edema
Pitting edema is swelling from extra fluid trapped in the tissues, usually in the legs, ankles and feet, that leaves a dent when pressed. Little research on supplements for it has been reviewed here so far, though potassium and horse chestnut have the most support, and one small pilot study looked at dandelion. Since causes range from heart, kidney and liver trouble to pregnancy, the underlying reason matters, and the evidence is limited.
- Best evidence:
Proximal Myotonic Myopathy
Proximal myotonic myopathy, also called myotonic dystrophy type 2, is a genetic muscle disorder where a gene change causes weakness in the hips, thighs and shoulders, plus muscles that are slow to relax. Vitamin D and creatine have the best evidence among supplements, and in a small study of 20 people, creatine eased fatigue. That evidence is limited, and there are no trial results here for vitamin D yet.
- Best evidence:
Pulmonary Hypertension
Pulmonary hypertension is high blood pressure in the arteries of the lungs, which makes the right side of the heart work harder and can lead to right heart failure. Iron has the strongest evidence among supplements, moderate, with symptoms improving when low iron was corrected, while small studies of inhaled vasoactive intestinal peptide found lower lung artery pressure and better cardiac output. Most other supplements, such as coenzyme Q10, have only limited evidence.
- Best evidence:
Schizoaffective Disorder
Schizoaffective disorder is a long-term condition that blends psychosis, such as hallucinations, delusions and disorganized thinking, with episodes of depression or mania. Among supplements, omega-3 fatty acids and vitamin D have the strongest research behind them, each rated moderate, drawing on roughly 1,200 and 1,500 participants. Theanine is far less studied: two small studies of about 40 people found anxiety symptoms improved, but the evidence is limited.
- Best evidence:
Sickle Cell Disease
Sickle cell disease is an inherited blood disorder in which red blood cells turn rigid and sickle-shaped, blocking blood flow and causing pain crises and organ damage. Evidence is moderate for folic acid, zinc and vitamin D, and studies of the antioxidant alpha-lipoic acid found oxidative stress markers went down. That finding is limited, though, drawn from four small studies with about 60 people.
- Best evidence:
Subfertility
Subfertility means conceiving takes longer than expected, arising from ovulation problems, blocked tubes, endometriosis, low sperm count or motility, or sometimes no identified cause. The evidence is strongest for folate and myo-inositol, the latter especially in PCOS-related infertility, while kisspeptin-54 injections stimulated luteinizing hormone release in healthy women and those with hypothalamic amenorrhea. That kisspeptin work measured hormone release rather than pregnancies, and in one study repeated dosing made the response fade.
- Best evidence:
Traveler's Diarrhea
Traveler's diarrhea is a gut illness, usually caused by bacteria such as E. coli from contaminated food or water, that irritates the intestine and brings loose, frequent stools. The evidence is strongest for Saccharomyces boulardii, a probiotic yeast, and for oral rehydration salts, which replace lost fluids. Evidence for the rest is thinner: a small study of 90 people found colostrum eased abdominal pain, while berberine and charcoal remain limited.
- Best evidence:
Tuberculosis (TB)
Tuberculosis is a bacterial infection of the lungs, caused by Mycobacterium tuberculosis and spread through airborne droplets, that takes months of antibiotics to clear. Vitamin D and zinc have the most research as nutritional support alongside those medicines, with moderate evidence for each, and in one small study of 120 people, height went up with vitamin D. Evidence for vitamin A, arginine, and vitamins C and E is limited, so the picture is still early.
- Best evidence:
Uremic Pruritus
Uremic pruritus is persistent itching that often affects people with chronic kidney disease, especially those on dialysis, and it seems to stem from a buildup of waste products, inflammation, and changes in the skin. Little research on supplements for it has been reviewed here so far. Evening primrose oil and omega-3 fatty acids are the main ones looked at, but the evidence for both is limited, so it's early days.
- Best evidence:
Varicose Veins
Varicose veins are enlarged, twisted veins, usually in the legs, that bulge when faulty valves let blood pool instead of flowing back toward the heart. The evidence is strongest for horse chestnut extract and diosmin with hesperidin, and in trials of gotu kola, signs of chronic venous insufficiency improved. Those gotu kola studies were small, though, and rutin did not erase bulging veins or fix failing valves.
- Best evidence:
Vascular Cognitive Impairment
Vascular cognitive impairment is a decline in thinking skills caused by poor blood supply to the brain, from strokes, small vessel disease, or long-term reduced blood flow, and it can progress to vascular dementia. Ginkgo biloba and citicoline have the most attention for it, and in one small pilot study of 80 people, blood flow in the brain went up with ginkgo. That is limited evidence from a single short study, and it measured blood flow rather than memory or daily thinking, so it says little yet about whether people thought more clearly.
- Best evidence:
Diarrhea Predominant Irritable Bowel Syndrome (IBS-D)
IBS-D is a gut disorder where recurring belly pain comes with loose stools, driven by an oversensitive gut-brain connection and altered gut movement rather than visible damage. The evidence is strongest for enteric-coated peppermint oil, which relaxes gut muscle, and moderate for IBS-specific probiotics. One trial of 121 people found symptom scores fell by about half with a curcumin and fennel oil blend, but fennel's own role is unclear.
- Best evidence:
Acute Back Pain
Acute back pain is a sudden ache that lasts under six weeks, usually from a strained muscle, sprained ligament, or minor disc problem. Among supplements, curcumin and devil's claw have some of the most research behind them, and in one small study of 108 people, pain eased with devil's claw. Still, that evidence is limited, and most episodes settle within a few weeks anyway, especially for people who stay active.
- Best evidence:
Antibiotic-Associated Diarrhea (AAD)
Antibiotic-associated diarrhea is loose, frequent stools that can follow a course of antibiotics, which disturb helpful gut bacteria and let opportunistic microbes overgrow. The evidence is strongest for the probiotics Saccharomyces boulardii and Lactobacillus GG, and human trials of Lactobacillus acidophilus, paired with other Lactobacillus strains, found people had diarrhea less often. That acidophilus evidence is moderate and rests on two studies, while kefir, prebiotics, glutamine and zinc have only limited support.
- Best evidence:
Antidepressant-Induced Sexual Dysfunction (AISD)
Antidepressant-induced sexual dysfunction is a common side effect of SSRIs and SNRIs, where extra serotonin dampens dopamine and norepinephrine pathways, lowering libido and arousal or delaying orgasm. Maca and saffron are the supplements studied most directly for it, though little research on them has been reviewed here so far. Ginkgo, L-arginine and ashwagandha have drawn interest too, but their evidence is limited, so it is early to say how well any work.
- Best evidence:
B5 Deficiency
B5 deficiency is a shortage of pantothenic acid, a vitamin the body needs to build coenzyme A, which helps turn food into energy; it is very rare and mostly seen with severe malnutrition. Vitamin B5 itself has the strongest evidence, and in a large study of 200 people, deficiency symptoms went down. That comes from a single set of results, so it says little about anything beyond those symptoms.
- Best evidence:
Beta-Thalassemia/Hb E
Beta-thalassemia is an inherited blood disorder in which the body makes abnormal hemoglobin, leading to anemia of varying severity, including the Hb E form common in Southeast Asia. The evidence is strongest for vitamin D and calcium, which support bones at risk from osteoporosis, a major complication. Curcumin is far less studied: one small study of 21 people found antioxidant enzyme levels went up, but the evidence is limited.
- Best evidence:
Breast Engorgement
Breast engorgement happens when the breasts fill with more milk than has been removed, causing swelling, pain and hardness, most often in the first days after birth when milk comes in. Lecithin and probiotics are the main supplements looked at, each with moderate evidence, though they were studied mainly for plugged ducts and mastitis rather than engorgement itself. A small serrapeptase study of 70 people found breast tenderness improved, but that evidence is limited.
- Best evidence:
Cancer-Related Pain
Cancer pain can come from a tumor pressing on tissues or nerves, from treatments like surgery, radiation or chemotherapy, or from general weakness, and it is common in advanced disease. Vitamin D and omega-3 fatty acids have the strongest supplement evidence, though only moderate, and in small trials of cannabis extracts pain improved. Those cannabis studies were limited, six in all with 39 people, and involved pain that persisted despite strong opioids.
- Best evidence:
Celiac Disease
Celiac disease is an autoimmune condition in which gluten, a protein in wheat, barley, and rye, turns the immune system against the small intestine's lining, impairing nutrient absorption. Evidence is strongest for iron and vitamin D, since the injured gut absorbs both poorly, and anemia was found in roughly 10 to 40 percent of people at diagnosis. Still, a strict gluten-free diet remains the only established approach, and evidence is limited for omega-3s.
- Best evidence:
Central Diabetes Insipidus
Central diabetes insipidus is a condition in which the brain doesn't release enough vasopressin, the hormone that tells the kidneys to hold on to water, so the body passes large amounts of dilute urine. Desmopressin, a lab-made version of that hormone, has the strongest evidence, and studies found it sharply reduced urine output and brought fluid balance back to normal. It is a medicine rather than a supplement, and the research comes from many studies, so a doctor guides its use.
- Best evidence:
Infantile Colic
Infant colic is long, hard-to-soothe crying in an otherwise healthy baby, usually starting around 2 to 3 weeks of age and fading by 3 to 4 months, though its cause is not well understood. The probiotic Lactobacillus reuteri has the most research, and reviews of 8 studies found babies cried less, with moderate evidence. Those studies covered only 323 babies in total, so more and larger trials would help firm things up.
- Best evidence:
Copper Deficiency
Copper deficiency is a condition in which the body lacks enough copper, a mineral that helps enzymes build connective tissue, make red blood cells and support nerve function. Copper is the supplement with the clearest research here, and the evidence is strong that blood copper levels went up. That finding is about a lab measure, though, and it doesn't tell us how symptoms changed for people with the condition.
- Best evidence:
Cutaneous T-Cell Lymphoma
Cutaneous T-cell lymphoma is a cancer of white blood cells called T cells that settle in the skin, causing patches, plaques, or tumors. Romidepsin, a prescription drug, has the strongest evidence: in two trials of people whose disease had returned or persisted, about a third responded, and 6% had a complete response. Those results apply mostly to advanced or relapsed disease, and most responses were partial.
- Best evidence:
Detoxification
Detoxification is the body's work of turning unwanted compounds, from food, medicines and its own metabolism, into forms it can clear, mostly through liver enzymes and then out in bile and urine. Among supplements, molybdenum is the one with research so far, and a study found that aldehyde metabolism went up. The evidence is limited, though, since it came from a small study of about 100 people.
- Best evidence:
Discirculatory Encephalopathy (DE)
Discirculatory encephalopathy is a long-term condition in which reduced blood flow damages the small vessels supplying the brain, leading to gradual memory problems and slower thinking; it is closely related to what Western medicine calls vascular cognitive impairment. Among supplements, vinpocetine has the most directly relevant finding, as cognitive symptoms improved in one small study. That study included only 20 people, so the evidence is limited, and larger trials in this exact condition are still needed.
- Best evidence:
Drug Metabolism
Drug metabolism is the way the body, mainly the liver, uses enzymes to break down medicines and other compounds so they can be used and cleared away. Black pepper's piperine has the most support here, and research found it blocked some of these enzymes and improved absorption of nutrients like CoQ10 and beta-carotene, while molybdenum saw drug clearance go up. The evidence is moderate for black pepper and limited for molybdenum, and the studies were fairly small.
- Best evidence:
Dry Mouth
Dry mouth, or xerostomia, happens when the salivary glands make too little saliva, which normally protects teeth and helps with swallowing, speaking and digestion. Betaine has the clearest research, and in a randomized trial of a betaine-containing toothpaste, people reported that their dry mouth symptoms eased. The evidence is moderate, though it rests on one trial of 188 people and the improvement was small.
- Best evidence:
Eisenmenger Syndrome
Eisenmenger syndrome is a complication of an untreated large hole in the heart, where years of extra blood flow stiffen the lung vessels until pressure rises and oxygen-poor blood crosses into the body's circulation. Iron is rated moderate for this condition and citrulline limited, and small studies of citrulline found blood pressure came down. Those studies involved only about 25 people in total, so the findings are early.
- Best evidence:
Fall Prevention
Falls happen when balance, muscle strength, vision, or footing fails, and weak muscles and fragile bones in older adults make injuries more likely. Vitamin D is among the supplements with the strongest evidence, and pooled trials covering about 2,400 people found fall risk improved, with a moderate-sized effect. Results mostly apply to older adults, including nursing home residents, especially those low in vitamin D.
- Best evidence:
Food Allergy
A food allergy is an exaggerated immune response to a specific food (commonly eggs, milk, peanuts, or shellfish), resulting in symptoms such as hives, wheezing, trouble swallowing, feeling faint, or gastrointestinal distress. In severe cases, anaphylaxis can occur.
- Best evidence:
Golf Performance
Golf is a precision sport that demands steady focus, fine motor control, and stamina over four to five hours of play. Caffeine and omega-3 fatty acids have the best-rated evidence, both moderate, and were looked at for focus and reaction time. Golf-specific data are thin, though: one small study of 20 people found phosphatidylserine improved performance measures.
- Best evidence:
Gum Health
Gum disease is a range of conditions, from mild gingivitis, where gums become inflamed, to severe periodontitis, which can damage the tissue and bone that hold teeth in place and lead to tooth loss. Coenzyme Q10 and vitamin C are the supplements most often looked at for gum health, though little research on them has been reviewed here so far. Both have a moderate evidence rating overall, but that is a general picture, and it is too early to say what specific trials found for gums.
- Best evidence:
Hair Health
Hair health reflects how well the follicles in your scalp grow strands that are strong, thick and anchored, a process shaped by hormones, nutrition and the natural cycle of hair growth and rest. Among supplements, GHK-Cu and vitamin B5 have the most reviewed research, and small studies found hair growth went up with GHK-Cu and hair strength went up with vitamin B5. The evidence for both is limited, since the trials were small, so firm conclusions aren't possible yet.
- Best evidence:
Hangover
A hangover is the rough morning after heavy drinking, driven by alcohol and its toxic byproduct acetaldehyde, along with dehydration, lost electrolytes, poor sleep and an irritated stomach. Among supplements, dihydromyricetin, electrolytes and ginger have the strongest support, each rated moderate, and ginger's backing comes from a systematic review of nausea and vomiting. That review looked at nausea in general rather than hangovers specifically, and detailed hangover results for the others are thin, so the picture is still early.
- Best evidence:
Hemophilia
Hemophilia is an inherited bleeding disorder in which too little of a clotting protein, factor VIII or factor IX, means bleeding lasts longer, often into joints and muscles. Desmopressin has the strongest evidence, and studies found it raised factor VIII activity two- to four-fold, enough for minor surgery in mild hemophilia A without factor concentrates. Those findings concern mild hemophilia A; vitamin D and calcium for bone health have only moderate evidence.
- Best evidence:
High-Altitude Performance
High altitude means less available oxygen, which stresses the body above about 2500 metres until it adapts with more red blood cells, faster breathing and higher cardiac output. Iron and beetroot juice nitrates have the best evidence, rated strong and moderate respectively, and a small trial in low-oxygen air found caffeine improved muscular endurance. That caffeine study had only eight people, so it is a hint rather than a firm answer.
- Best evidence:
Ice Hockey Performance
Ice hockey performance is the ability to produce explosive power, speed and agility across repeated high-intensity efforts while handling physical contact. Creatine is a main supplement people look at for this, and studies found anaerobic capacity improved. That evidence is limited, though: the studies were small and involved just 17 people in total, so the picture for hockey players is still early.
- Best evidence:
Idiopathic Asthenozoospermia
Idiopathic asthenozoospermia means sperm have reduced movement without a clear cause, which makes it harder for them to swim to and fertilize an egg. Coenzyme Q10 and L-carnitine have the most research behind them, and studies of coenzyme Q10 found sperm motility improved. That evidence is limited, though: it rests on two small studies with 22 men in total, and one was an open pilot without a comparison group.
- Best evidence:
Inflammatory Venous Disease
Inflammatory venous disease, including chronic venous insufficiency and varicose veins, happens when inflamed, weakened veins and damaged valves let blood pool in the legs, causing swelling, pain and skin changes. Horse chestnut seed extract and diosmin-hesperidin have the strongest evidence, and in one small trial of 40 people, serrapeptase improved pain. Still, the serrapeptase evidence is limited, and compression stockings and exercise remain the foundation.
- Best evidence:
Intrauterine Growth Restriction
Intrauterine growth restriction is when a baby in the womb grows more slowly than expected, usually because the placenta isn't delivering enough blood, oxygen and nutrients. The evidence is strongest for low-dose aspirin, which supports placental blood flow, with moderate evidence for omega-3 fatty acids and L-arginine. Aspirin is a prescription medicine, and fish oil studies were small, with birth weight changing in a direction that stayed unclear.
- Best evidence:
Iron Metabolism
Iron metabolism is how the body absorbs, stores, transports and recycles iron, which it needs to make hemoglobin, the red blood cell protein that carries oxygen. Copper has the clearest support among supplements, and trials found hemoglobin levels went up, with moderate evidence. That finding comes from about 250 participants, so it is a useful signal rather than the final word.
- Best evidence:
Longer Lifespan
Aging is the gradual wearing down of cells and tissues, driven by things like DNA damage, shortening telomeres, tired mitochondria, and lingering inflammation. Omega-3 fatty acids and vitamin D have the strongest evidence among supplements people explore for healthy aging, with studies involving thousands of people. Still, no supplement has been shown to extend human lifespan, and a small trial of astragalus found no clear difference in telomere length.
- Best evidence:
Manganese Deficiency
Manganese deficiency is a shortfall of a trace mineral that helps enzymes build bone, process nutrients and protect cells, and it is rare with a varied diet. Manganese supplements have the strongest evidence here: in a large body of research covering 400 people, blood manganese levels went up. That shows the mineral reaches the bloodstream, but it doesn't tell us whether symptoms changed.
- Best evidence:
Muscle Cramps
Muscle cramps are sudden, painful contractions of a muscle, most often in the calves, feet, or back, and they can follow dehydration, electrolyte shifts, tired muscles, or certain medications. People most often look at magnesium and electrolytes such as sodium and potassium, but little research on them has been reviewed here so far. One trial of pickle juice found it inhibited cramps brought on by electrical stimulation, so the evidence there is limited.
- Best evidence:
Nocturnal Enuresis
Nocturnal enuresis is bedwetting during sleep, which happens when a child's body makes a lot of urine overnight, the bladder holds little, or sleep is too deep to notice a full bladder. Among options studied, the evidence is strongest for desmopressin, and trials found about 2.2 fewer wet nights per week than placebo. Still, only about 35% of children became completely dry, and a review also described cases of severe low blood sodium.
- Best evidence:
Obstructive Sleep Apnea (OSA)
Obstructive sleep apnea is a sleep disorder in which the airway repeatedly collapses during sleep, causing breathing pauses and drops in oxygen. Vitamin D has drawn the most interest because low levels are common in people with it, though the evidence is limited, and in five melatonin studies insomnia symptoms improved. Evidence for omega-3s, magnesium and N-acetyl cysteine is limited too, and the melatonin findings concern sleeplessness, not breathing pauses.
- Best evidence:
Ocular Hypertension
Ocular hypertension is eye pressure above the usual range, typically over 21 mmHg, without damage to the optic nerve, and it is the main risk factor for glaucoma. Cannabis is the one option with reported findings: two small studies found eye pressure went down, though the evidence is limited. Those studies included only six people in total, so the results are early hints rather than firm answers.
- Best evidence:
Optimal Nutrient Levels
Optimal nutrient levels means having enough of the vitamins and minerals your body relies on for bones, nerves and immunity, which diet, age or little sun can make harder. The evidence is strongest for vitamin D, omega-3s and magnesium, and a global review called vitamin D shortfalls a widespread problem. Separately, piperine from black pepper increased how much curcumin people absorbed, though that came from only about 60 people.
- Best evidence:
Perinatal Depression
Perinatal depression is low mood that arises during pregnancy or after birth, when big hormone shifts and disrupted sleep can change how the brain regulates mood. Omega-3 fats from fish oil have the most research behind them, and trials found depression symptoms eased. Still, the evidence is limited, the studies were small, and vitamin D, iron, folate and probiotics have even less to go on.
- Best evidence:
Peyronie's Disease
Peyronie's disease is the development of scar tissue on the penis due to repeated injury. This disease can cause painful erections and sexual dysfunction.
- Best evidence:
Postural Orthostatic Tachycardia syndrome (POTS)
POTS is a form of dysautonomia in which the autonomic nervous system doesn't steady heart rate and blood vessel tone on standing, leaving people lightheaded, tired, foggy, or faint. The evidence is strongest for sodium, which helps expand blood volume, and moderate for vitamin D and iron, whose deficiencies are common in POTS. In four small vitamin C studies, blood flow went up, but they included only 19 people, so that evidence is limited.
- Best evidence:
Raynaud's Phenomenon
Raynaud's phenomenon is a condition in which blood vessels in the fingers and toes narrow in response to cold or stress, turning the skin white, then blue, then red as blood flow returns. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Omega-3 fatty acids and ginkgo biloba are often discussed for circulation, but that is still a hypothesis.
- Best evidence:
Sarcoidosis
Sarcoidosis is an inflammatory disease in which clusters of immune cells called granulomas form, most often in the lungs and lymph nodes, for unknown reasons. Omega-3 fatty acids and curcumin draw the most interest as anti-inflammatory options, but the evidence for both is limited, and a tiny quercetin study of 12 people found no clear difference in inflammation. Vitamin D and calcium are special cases, since granulomas can activate vitamin D and raise blood calcium.
- Best evidence:
Scabies
Scabies is a contagious skin infestation in which tiny mites burrow into the skin, causing intense itching that is often worst at night. Tea tree oil, neem oil, zinc and vitamin C are the supplements people most often look at alongside standard care, but little research on them has been reviewed here so far. Any evidence that exists is limited, so it is too early to say how much they might add.
- Best evidence:
Sinusitis
Sinusitis is inflammation of the sinuses, the air-filled spaces behind your forehead, cheeks and nose, and it can be short-term or last more than 12 weeks. Among supplements, N-acetyl cysteine and serrapeptase are the ones people look at most, since both may thin mucus and ease swelling. Little research on any of them has been reviewed here so far, so there are no findings to report yet, and the evidence looks moderate for N-acetyl cysteine and limited for serrapeptase.
- Best evidence:
Ski Performance
Ski performance draws on endurance, explosive power and balance, made harder by cold and the thin air of altitude. The evidence is strongest for caffeine, with beetroot juice and creatine at a moderate level, thanks to their roles in oxygen efficiency and high-intensity power. Skiing-specific findings are thin, though: in one small study of 24 people, branched-chain amino acids eased fatigue, but that evidence is limited.
- Best evidence:
Smoking Behavior
Nicotine dependence keeps people smoking because nicotine acts on brain chemicals like dopamine and glutamate, so stopping brings cravings, irritability and trouble concentrating. Little research on supplements for quitting has been reviewed here so far, so there are no trial findings to share yet. Ideas about N-acetyl cysteine and vitamin C rest mostly on how they might work, and quitting often takes 8 to 11 tries.
- Best evidence:
Sore Throat
A sore throat, or pharyngitis, is pain, scratchiness, or irritation in the throat that often worsens when swallowing, and it is usually caused by a viral infection. Zinc and vitamin C are the two supplements most often looked at for it, but little research on them for sore throat specifically has been reviewed here so far. Honey, elderberry, and slippery elm are also popular, though this page can't yet say what trials found for any of them.
- Best evidence:
Staphylococcal Bacteremia and Endocarditis
Staphylococcal bacteremia means Staphylococcus bacteria have entered the bloodstream, and endocarditis is an infection of the heart's inner lining or valves. The strongest evidence is for daptomycin, an intravenous antibiotic: in 246 people, treatment success at 42 days was similar to standard therapy, and adding a second antibiotic did not improve outcomes. It matched standard care rather than beating it, and the endocarditis results covered right-sided infections.
- Best evidence:
Substance Use Disorder
Substance use disorder is a medical condition in which people keep using alcohol or drugs despite harm, because reward, stress, and self-control circuits in the brain have been altered. Among supplements, N-acetylcysteine has drawn the most attention, and trials in people dependent on cocaine found their addiction symptoms improved. Only two small studies, covering about 245 people, back this up, so the evidence is limited.
- Best evidence:
Sulfite Sensitivity
Sulfite sensitivity is an adverse reaction to sulfites, preservatives common in wine and dried fruit, and it can involve trouble breaking them down with an enzyme called sulfite oxidase. Molybdenum, a mineral that enzyme relies on, has the clearest research: studies found sulfite oxidase activity went up, and the evidence is moderate. That result covers about 180 people and tracks the enzyme itself, so it says little yet about whether symptoms eased.
- Best evidence:
Symptoms of Withdrawal
Withdrawal symptoms are the physical and emotional discomfort that can follow when the body, adapted to a substance such as opioids or alcohol, suddenly has less of it, leaving the nervous system overactive and out of balance. Among supplements, delta sleep-inducing peptide has the most to show, and studies found opioid withdrawal severity went down. The evidence is limited, though: the research is older, dating to the 1980s, and it comes from a small number of studies with 167 people in all.
- Best evidence:
Tardive Dyskinesia (TD)
Tardive dyskinesia is a movement disorder of involuntary, repetitive movements, often in the face, tongue, and jaw, that can develop after long-term use of certain psychiatric medications, especially older antipsychotics. Vitamin E and vitamin B6 have the most research behind them, and some studies found signs of benefit for symptoms, though the evidence for each is limited. The studies were modest in size, and vitamin E seemed less helpful once the movements were already established.
- Best evidence:
Tobacco Use Disorder
Tobacco use disorder, often called nicotine addiction, is a condition in which nicotine creates strong physical and psychological dependence, which is why quitting is so hard. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report for NAC or vitamin C, the two most often discussed. Both have only limited evidence behind them, and ideas about cravings or oxidative stress remain largely theoretical for now.
- Best evidence:
Trismus
Trismus, often called lockjaw, is a limit on how wide the mouth opens, usually because the jaw muscles tighten or swell after surgery, injury or radiation. Serratiopeptidase, an enzyme supplement, has the most direct trial data, and studies after wisdom tooth surgery found inflammation went down. Those studies were small, about 110 people in all, so the evidence is limited and mostly reflects dental surgery.
- Best evidence:
Vaginal Health
Vaginal health rests on a balance of bacteria, with Lactobacillus species producing lactic acid that keeps the vagina acidic. Little research on supplements for this has been reviewed here so far, though Lactobacillus probiotics, especially L. rhamnosus and L. reuteri, are the most studied option, with cranberry and vaginal boric acid also discussed. Without trial findings to report, it is too early to say how well any of them work.
- Best evidence:
Variceal Bleeding
Variceal bleeding happens when swollen veins in the food pipe or stomach, enlarged by high pressure in the liver's blood supply, tear and bleed. The evidence is strongest for terlipressin: trials found that people with acute bleeding who received it were less likely to die than those given placebo, roughly a third lower relative risk. That result covers deaths from any cause during acute bleeding, and little other research on this condition has been reviewed here so far.
- Best evidence:
Vertigo
Vertigo is the sensation that you or your surroundings are spinning, usually driven by a problem in the inner ear's balance system, though sometimes by the brain itself. Vitamin D and ginkgo biloba have the most research behind them, with moderate evidence, and in one small trial of ginger, dizziness improved. That ginger study involved just 8 people, so the evidence there is limited.
- Best evidence:
Vitamin D Deficiency
Vitamin D deficiency means the body has too little of a hormone-like nutrient that supports bones, immune function and mood in nearly every cell. Vitamin D3 has the strongest evidence among supplements, with vitamin K2 and magnesium at a moderate level, and pooled trials found depression symptoms eased with vitamin D. That finding came from five small trials of 679 people, so it says little about bones or immunity.
- Best evidence:
Zollinger-Ellison Syndrome
Zollinger-Ellison syndrome is a condition in which gastrin-producing tumors, called gastrinomas, push the stomach to make far too much acid, causing stubborn ulcers and diarrhea. Secretin, a hormone used in a clinic test, has the best-supported evidence, which is strong: studies found it detected gastrinoma with 92 to 96 percent sensitivity and 100 percent specificity. That held in properly controlled studies, though it is a test for finding tumors, not a symptom remedy.
- Best evidence:
Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome is a serious lung condition in which inflammation and fluid leaking into the tiny air sacs stop oxygen from reaching the blood. Among supplements, only vasoactive intestinal peptide, also called aviptadil, has been studied, and the evidence is rated strong, but trials gave mixed results: a smaller trial found better survival at 60 days, while a larger one found no difference. So whether it helps remains uncertain, and the findings mostly come from people critically ill with COVID-19.
- Best evidence:
Adjustment Disorder
Adjustment disorder is a stress-related condition in which someone struggles to cope with a major life change, such as a breakup, job loss, or illness, and develops sadness, anxiety, or sleep trouble beyond what would be expected. Little research on adjustment disorder itself has been reviewed here so far, though ashwagandha and lavender oil have moderate evidence for stress and anxiety more broadly. That wider work may not carry over neatly, so how well they help with this condition remains unclear.
- Best evidence:
Ankylosing Spondylitis
Ankylosing spondylitis is a chronic autoimmune disease, tied to the HLA-B27 gene, in which inflammation of the spine and sacroiliac joints causes pain and stiffness and can eventually fuse the vertebrae. Among supplements, thunder god vine has been tried, and a small case series found disease activity measures improved over six weeks. Only 12 people took part, with no comparison group, so the evidence is very limited.
- Best evidence:
Aromatase-Inhibitor Related Joint Pain
Aromatase-inhibitor joint pain is aching and stiffness in the hands, wrists, knees and feet that affects many women taking these breast cancer medicines, and it is thought to stem from the drop in estrogen affecting joints and cartilage. Vitamin D and omega-3 fatty acids are the supplements most often looked at for it, but little research on them has been reviewed here so far. Because of that, it is too early to say how much either one helps.
- Best evidence:
Bladder Cancer
Bladder cancer begins when cells in the bladder lining grow out of control, with smoking as the leading risk factor. Vitamin D has the strongest support among supplements, rated moderate, with low levels linked to bladder cancer outcomes, while green tea extract is limited, backed mainly by studies linking green tea to lower risk. Salidroside slowed bladder cancer cells in a lab dish, but that work has no human confirmation.
- Best evidence:
Bowel Cleansing
Bowel cleansing is the process of emptying the colon before a colonoscopy, surgery, or imaging test, usually with a clear liquid diet and a large volume of prep solution that can leave the gut dehydrated and its microbiome disrupted. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Electrolytes, probiotics, and simethicone are the most discussed options, but that reflects their proposed roles rather than results.
- Best evidence:
Brachial plexus damage
Brachial plexus damage is an injury to the network of nerves running from the neck through the armpit that controls movement and feeling in the shoulder, arm, and hand, and it can cause weakness, numbness, or paralysis of the arm. Vitamin B12 and alpha-lipoic acid are the supplements most often discussed for nerve health, though little research on them for this specific injury has been reviewed here so far. Any nerve-support ideas for now rest mostly on how these nutrients work in the body rather than on direct trial results.
- Best evidence:
Breath Holding Spells
Breath-holding spells are involuntary episodes in which a young child, usually between 6 months and 6 years old, stops breathing after crying from pain, frustration, or a scare, sometimes turning blue or pale and briefly fainting. They are not voluntary or manipulative. Little research on supplements for them has been reviewed here so far, so there are no trial findings to report yet. Iron is the supplement most often discussed, because low iron is closely linked to these spells.
- Best evidence:
C. difficile
C. difficile is a bacterium that causes severe diarrhea and colitis, mostly after antibiotics upset the gut's normal microbes and let it overgrow and release toxins that damage the intestinal lining. Probiotics, including a Lactobacillus combination, are the main supplements people look at, and a review found supportive evidence for them in lowering the chance of infection, though the evidence is limited. Much of that support came from animal or lab work, so it says less about how people fare.
- Best evidence:
Cannabis Use Disorder
Cannabis use disorder is a pattern of cannabis use that becomes hard to control and causes real problems or distress, often with cravings and withdrawal such as irritability, poor sleep and restlessness when someone stops. N-acetyl cysteine, which influences the brain's glutamate signaling, is the supplement with the most support, and the evidence for it is moderate. Little research on specific findings has been reviewed here so far, and the evidence for omega-3s, magnesium, ashwagandha and others is limited.
- Best evidence:
Carbonic Anhydrase VI Deficiency
Carbonic anhydrase VI deficiency is a shortage or malfunction of an enzyme in saliva that helps balance mouth acidity, buffers acid that would otherwise wear at teeth, and supports taste buds. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Because the condition is rare and under-recognized, what is known about oral health support comes mostly from studies of the wider population rather than people with this deficiency.
- Best evidence:
Charcot-Marie-Tooth Disease Type 1A (CMT1A)
Charcot-Marie-Tooth disease type 1A is an inherited condition of the peripheral nerves, the ones outside the brain and spinal cord, that brings gradual muscle weakness and wasting, usually starting in the feet and legs, along with numbness, tingling and high-arched feet. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Vitamin D, acetyl-L-carnitine and B vitamins are the ones most often discussed, but that reflects interest rather than proven results.
- Best evidence:
Healthy Childhood Development
Healthy childhood development is the growth of a child's body, thinking, emotions and movement, with the brain changing fastest in the first few years and leaning heavily on nutrition. Omega-3 DHA, vitamin D, iron and iodine have the strongest evidence, yet the one DHA trial found no clear difference in children's behavior. It was a small study of 132 preterm children whose mothers received DHA, so the evidence there is very limited.
- Best evidence:
Chronic Bronchitis
Chronic bronchitis is a form of COPD in which inflamed bronchial tubes make extra mucus, causing a productive cough on most days, usually because of smoking. Little research on supplements for it has been reviewed here so far, though N-acetylcysteine and vitamin D carry the strongest evidence. Both are studied mainly for fewer flare-ups, and vitamin D may matter most for people who are low in it.
- Best evidence:
Chronic Progressive External Ophthalmoplegia (CPEO)
Chronic progressive external ophthalmoplegia, or CPEO, is a mitochondrial disease in which the cells' energy machinery works poorly, slowly weakening the muscles that lift the eyelids and move the eyes. Coenzyme Q10 and L-carnitine are the supplements most often discussed for it, though little research on them in CPEO has been reviewed here so far. Because no trial findings are available to report, it's hard to say how well any supplement works for this condition.
- Best evidence:
Chronic Pulmonary Disease
COPD is a progressive lung condition, usually caused by smoking, in which inflamed, mucus-filled airways and damaged air sacs leave airflow partly blocked, causing breathlessness and a persistent cough. Little research on supplements for it has been reviewed here so far, though one meta-analysis looked at creatine for muscle weakness. Vitamin D and NAC draw the most interest, but without trial findings yet, it is too early to say how much either helps.
- Best evidence:
Claustrophobia
Claustrophobia is an anxiety disorder in which the brain's fear circuits react strongly to enclosed spaces, driven by an overactive stress response and altered neurotransmitter signaling. Among supplements, yohimbine has been looked at most, and small trials found phobia symptoms improved when it was added to exposure-based therapy. The evidence is limited, though: only two small studies with 24 participants contributed, and one tested fear of flying rather than enclosed spaces.
- Best evidence:
Colorectal Polyps
Colorectal polyps are small growths on the inner lining of the colon or rectum, and while most are harmless, some types called adenomas can slowly turn into colorectal cancer over time. Calcium and vitamin D have the most support as supplements people look at for polyps, with the evidence rated moderate for each, though little trial research on them has been reviewed here so far. Fiber and omega-3s also have moderate evidence, while the rest, such as folate, probiotics and green tea extract, rest on limited data.
- Best evidence:
Copper Status
Copper status describes how much copper your body holds and how well it absorbs and uses it, which matters because copper helps enzymes handle iron, build connective tissue, and make cellular energy. Molybdenum is the supplement with research so far, and a small study of 100 people found it may reduce copper absorption. The evidence is very limited, so this is a hint rather than a firm answer.
- Best evidence:
Dehydration
Dehydration happens when the body loses more fluid than it takes in, which disturbs the water balance that temperature control, nutrient transport and waste removal depend on. Electrolyte blends and sodium have the strongest evidence as rehydration aids, along with potassium, glucose and zinc, which helps with diarrheal illness. Little research on these has been reviewed here so far, so it is too early to describe specific trial findings.
- Best evidence:
Diffuse Esophageal Spasm
Diffuse esophageal spasm is a condition in which the esophagus squeezes in an uncoordinated way instead of a smooth wave that pushes food down, causing chest pain and trouble swallowing. Peppermint oil, a smooth muscle relaxer, is the main supplement people look at, but little research on it has been reviewed here so far. Magnesium, ginger and melatonin come up too, with support mostly from how they act in the body.
- Best evidence:
Endocrine Function
Endocrine function describes how the body's hormone-producing glands, such as the thyroid, adrenals, pancreas and pineal gland, release chemical messengers that steer metabolism, growth, sleep and stress responses. Among supplements, the peptide epitalon has been looked at for pineal gland function, and studies found a small improvement in markers of how that gland worked. The evidence is limited, though: it rests on five small studies with 65 people in total, so it's too early to say how much this matters in daily life.
- Best evidence:
Esophageal Health
The esophagus is the muscular tube that carries food and liquid from the throat to the stomach, and its lining can be irritated or damaged by things like stomach acid moving upward. Molybdenum is the supplement with research so far, and the evidence is limited: esophageal cancer risk went down in research involving about 2,000 people. That work was small, so it points to a possible link rather than a clear answer.
- Best evidence:
Fatty Liver Disease
Fatty liver disease is when extra fat builds up in liver cells, often with excess weight and insulin resistance, and can inflame the liver. Retatrutide, a triple hormone agonist, has the strongest evidence, and liver fat fell by roughly 82 to 86 percent in a 48-week trial, with about nine in ten people reaching normal levels. That trial was mid-stage and included only 98 people, so larger, longer studies are still needed.
- Best evidence:
Fear of Flying
Fear of flying, or aviophobia, is a specific phobia in which the body's alarm system reacts strongly to air travel, from mild worry to avoiding planes altogether. L-theanine and oral lavender have the strongest evidence among calming supplements, rated moderate, though no flying-specific results were found for them. The only flying-related research found that yohimbine, paired with exposure therapy, improved phobia symptoms in two small studies of 48 people, so that evidence is limited.
- Best evidence:
Fragile X Syndrome
Fragile X syndrome is the most common inherited cause of intellectual disability and autism, arising when a change in the FMR1 gene on the X chromosome stops the body from making FMRP, a protein the developing brain needs. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Omega-3 fatty acids and melatonin have the most support in related areas, but that is not the same as evidence in people with Fragile X.
- Best evidence:
Functional Gastrointestinal Disorders
Functional gastrointestinal disorders are conditions in which the gut doesn't work as it should even though no structural damage shows up, with irritable bowel syndrome the best known, alongside functional dyspepsia, constipation and bloating. Probiotics and enteric-coated peppermint oil are the supplements with the strongest evidence, but little research on their specific findings has been reviewed here so far. Because effects of probiotics vary by strain, and other options like psyllium, ginger and artichoke leaf have only moderate evidence, it's still early to say what works best.
- Best evidence:
General Health
General health is the overall state of your body and mind, shaped by how well your organs, hormones, immune defenses and everyday metabolism work together. Tyrothricin, an antibiotic mixture, has the strongest evidence here, and the finding was a warning: across four studies, systemic use caused toxicity, including red blood cell breakdown and kidney damage. Its use has stayed limited to topical and local applications, and its toxicity resembles that of gramicidin, one of its components.
- Best evidence:
Graves’ Disease
Graves' disease is an autoimmune condition in which the body makes antibodies that push the thyroid to produce too much thyroid hormone, and it is the most common cause of an overactive thyroid. Among supplements, vitamin D has the clearest trial finding: bone density improved in people after Graves' disease treatment. The evidence is limited, though, and it comes from a small number of small studies.
- Best evidence:
Hand-Foot Syndrome
Hand-foot syndrome is a side effect of certain chemotherapy drugs that brings redness, swelling and pain to the palms of the hands and soles of the feet. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. People often ask about vitamin B6 and urea cream, but how well they work is still an open question.
- Best evidence:
Hip Fracture
A hip fracture is a break in the top of the thigh bone, usually after a fall when bones have thinned with age, and it typically needs surgery. Vitamin D, calcium and protein have the strongest evidence among supplements for supporting recovery, while studies of the drug teriparatide found fewer hip fractures for up to eight years afterward. That teriparatide evidence is moderate and centers on people with osteoporosis.
- Best evidence:
Human Papillomavirus (HPV)
Human papillomavirus (HPV) is the most common sexually transmitted infection, and while the immune system clears most infections on its own, some high-risk types linger in cervical cells and can lead to cancer over time. Supplements such as AHCC and indole-3-carbinol/DIM draw the most interest, but little research on them has been reviewed here so far. Any evidence that exists is limited, so these remain open questions rather than established options.
- Best evidence:
Huntington's Disease
Huntington's disease is an inherited condition in which a change in the huntingtin gene slowly damages brain cells that control movement, thinking, and mood. Coenzyme Q10 and creatine draw the most interest, with the evidence moderate for coenzyme Q10 and limited for creatine, but there are few trial results to report so far. Studies have been small, and no supplement has been shown to slow the disease.
- Best evidence:
Hyperemesis Gravidarum
Hyperemesis gravidarum is severe nausea and vomiting in pregnancy that goes beyond typical morning sickness, causing dehydration, weight loss and electrolyte imbalances. Vitamin B6 and ginger have the strongest evidence among supplements, and in nine ginger studies involving 321 people, nausea symptoms eased. Those studies were small, and the evidence for ginger was moderate, so how well it works in the most severe cases remains unclear.
- Best evidence:
Hyperpnoea-Induced Bronchoconstriction (HIB)
Hyperpnoea-induced bronchoconstriction, also called exercise-induced bronchoconstriction, is a temporary narrowing of the airways during or after hard exercise, when fast, heavy breathing dries and cools the airway lining. People often look at vitamin C, omega-3 fats and caffeine for it, but little research on them has been reviewed here so far. Ideas about how they might help, such as calming airway inflammation, remain largely theoretical for now.
- Best evidence:
Hyperthyroidism
Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone, speeding up the body's metabolism. Little research on supplements for it has been reviewed here so far, though L-carnitine and selenium have been studied in Graves' disease, with moderate evidence. Calcium with vitamin D is also studied because bone loss speeds up, but evidence for vitamin D or magnesium alone is limited.
- Best evidence:
Hypocarnitinemia
Hypocarnitinemia is a shortage of carnitine, the molecule that carries long-chain fatty acids into mitochondria to be burned for energy, so muscles tire, blood sugar can dip, and the heart may weaken. Little research on supplements for it has been reviewed here so far, apart from a review of B vitamins in energy metabolism. Causes range from inherited defects to dialysis or certain medications, so results may not carry across people.
- Best evidence:
Indigestion
Indigestion, or dyspepsia, is discomfort in the upper abdomen during or after eating, with causes that range from stomach acid to slow emptying. Ginger and artichoke leaf extract have the strongest evidence, rated moderate, but the findings available are for astaxanthin, where one trial of 132 people found mixed results on reflux symptoms. So the picture is unsettled: astaxanthin's evidence is limited, and no trial results were available for ginger or artichoke.
- Best evidence:
Intestinal Parasite Infection
An intestinal parasite infection happens when single-celled organisms like Giardia or worms like roundworm and hookworm settle in the digestive tract, often causing diarrhea, cramping, bloating, and nutrient loss. Oregano oil has the only trial reviewed here: people's parasite counts improved, and the evidence is limited. That study was tiny, with just 13 participants, so it cannot show how well oregano works, and other supplements like probiotics and berberine have no findings to report yet.
- Best evidence:
Intrahepatic Cholestasis of Pregnancy (ICP)
Intrahepatic cholestasis of pregnancy is a liver condition of the third trimester in which bile acids build up in the blood, causing intense itching, especially on the palms and soles, and it clears up after delivery. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Vitamins K, D and E are discussed because cholestasis can interfere with absorbing fat-soluble vitamins, but that is a rationale rather than a result.
- Best evidence:
Invasive Aspergillosis
Invasive aspergillosis is a serious infection where Aspergillus mold, breathed in from the air, grows in the lungs and can spread, mostly in people with weakened immune defenses. Caspofungin has moderate evidence, and some people whose infection resisted other antifungals responded to it. That rested on a small trial of under 100 patients, and because it slows fungal growth rather than killing it, it has mostly been used after other options.
- Best evidence:
Ischemic Mitral Regurgitation
Ischemic mitral regurgitation is a leak backward through the mitral valve that happens after a heart attack or from coronary artery disease, when damaged heart muscle no longer supports a valve that is often structurally normal. Among supplements, coenzyme Q10 and omega-3 fatty acids have drawn the most interest, but little research on them in this condition has been reviewed here so far. Their support comes from broader heart research, where the evidence is moderate, so it is not yet clear how they affect the leak itself.
- Best evidence:
Jet Lag
Jet lag is what happens when fast travel across time zones leaves your internal body clock out of step with local day and night, bringing poor sleep, daytime fatigue and trouble concentrating. Little research on supplements for it has been reviewed here so far, though melatonin has the strongest evidence. Caffeine has moderate evidence, while vitamin D, magnesium, L-theanine and valerian have limited evidence, so firm conclusions aren't possible yet.
- Best evidence:
Kashin-Beck Disease (KBD)
Kashin-Beck disease is a long-lasting bone and joint disorder found in parts of China, Siberia, and North Korea, in which cartilage breaks down and damages bone, causing joint pain, stiffness, and shortened fingers and limbs in children. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Selenium deficiency is a major contributing factor, alongside possible grain mycotoxins and low iodine.
- Best evidence:
Kidney Stones
Kidney stones are hard deposits of minerals and salts that form inside the kidneys and can cause severe pain as they pass through the urinary tract. Among supplements, potassium citrate has the strongest evidence and magnesium a moderate amount, with both studied in large groups of people. Boron, by contrast, had one small study of 14 people in which stone symptoms improved, so that evidence is limited.
- Best evidence:
Leukoplakia
Leukoplakia is a condition in which thick white patches form on the gums, inside the cheeks, under the tongue, or on the tongue itself; they can't be scraped off and are seen as potentially premalignant. Among supplements, beta-carotene and vitamin A have the most support, with the evidence rated moderate for each. Little research on leukoplakia has been reviewed here so far, so specific trial findings can't yet be described, and vitamin E, vitamin C and green tea extract have only limited evidence.
- Best evidence:
Nail Health
Nails are hard plates of keratin that grow about 3 to 4 millimeters a month, and brittleness, splitting or slow growth can reflect aging, harsh chemicals or a nutritional gap. Biotin, the best-studied option for brittle nails, and collagen peptides have moderate evidence, and collagen studies found improved nail growth and strength. Even so, the evidence is moderate at best, and a small gelatin study offered only limited support.
- Best evidence:
Neurological Function
Neurological function is how your brain, spinal cord, and nerves send signals that shape thinking, movement, sensation, and mood. Copper is the supplement with findings so far, and small research involving 80 people found that dopamine metabolism went up. Still, the evidence is limited and rests on one measure, so it is too early to say what that means for everyday thinking or movement.
- Best evidence:
Opioid Use Disorder
Opioid use disorder is a long-term medical condition in which opioid use becomes a pattern that causes real distress and disrupts daily life, driven by lasting changes in the brain's reward and stress systems. Supplements such as NAC and omega-3 fatty acids have drawn the most interest for cravings and mood in recovery, but little research on them has been reviewed here so far. Any interest in them is early, and they are not a substitute for established medical care.
- Best evidence:
Orthostatic Hypotension
Orthostatic hypotension is a sharp blood pressure drop on standing that brings lightheadedness, blurred vision and sometimes fainting, often from dehydration, medications or autonomic nerve problems. The evidence is strongest for sodium, which expands blood volume, and in one small trial of 31 people with autonomic failure, yohimbine eased symptoms. That yohimbine evidence is limited, and it mostly applies to people whose condition has a nerve-related cause.
- Best evidence:
Osteopenia
Osteopenia is bone density lower than normal but not low enough to count as osteoporosis, most often linked to aging, especially after menopause. Little research on supplements for it has been reviewed here so far, though calcium and vitamin D have the strongest evidence for bone health. Without trial results to lean on, it is too early to say how much any supplement changes bone density or fractures.
- Best evidence:
Otitis Media
Otitis media, or middle ear infection, is fluid behind the eardrum that becomes infected, usually after a cold. Xylitol and probiotics are the supplements people look at most for it, but little research on them has been reviewed here so far. Many ear infections ease on their own, though some in young children need antibiotics.
- Best evidence:
Ovarian Cancer
Ovarian cancer is a serious cancer that starts in the ovaries, and it often goes unnoticed until it has spread through the pelvis and abdomen, which makes it harder to manage at later stages. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Vitamin D, omega-3 fatty acids and ginger are the ones most often discussed, mainly for immune support and easing chemotherapy-related nausea.
- Best evidence:
Pain
Pain is the nervous system's alarm, with nerves sending signals that the brain and spinal cord weigh and amplify, and chronic pain is when that alarm keeps sounding long after an injury should have settled. Among supplements, the one with findings so far is DSIP, a small peptide, and studies found chronic pain intensity went down. That rests on just four small studies with 35 people in total, so the evidence is limited.
- Best evidence:
Pancreatic Cancer
Pancreatic cancer is a cancer of the pancreas, the organ that makes digestive enzymes and insulin, so it and its treatment often disrupt digestion and how the body handles nutrients. Little research on supplements for it has been reviewed here so far, though pancreatic enzymes and omega-3 fatty acids are the ones most often discussed. Curcumin has drawn interest from lab studies, but clinical data are limited.
- Best evidence:
Paranoia
Paranoia is a pattern of persistent, unfounded beliefs that others mean you harm, such as feeling watched, followed or talked about, and it can arise from severe stress, sleep loss, substance use, or conditions like schizophrenia and bipolar disorder. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Omega-3 fatty acids and vitamin D have been looked at most often in related psychosis research, but that work isn't specific to paranoia.
- Best evidence:
Pathological Gambling (PG)
Gambling disorder is a behavioral addiction in which people keep gambling despite real harm, tied to the brain's dopamine reward pathways and weakened impulse control. Little research on supplements for it has been reviewed here so far, though N-acetyl cysteine has been studied specifically for gambling, and the one review available looks at vitamin D and mental health more broadly. The evidence is moderate for N-acetyl cysteine and limited for everything else.
- Best evidence:
Peri-implant diseases
Peri-implant diseases are conditions affecting the gum and bone tissue around dental implants, much like gum disease affects natural teeth, and they involve inflammation driven by bacteria that can wear down the supporting bone. Vitamin D and calcium have been looked at most, because of their role in bone health, but little research on them has been reviewed here so far. Omega-3s and probiotics are also being explored, though the evidence for all four is limited.
- Best evidence:
Polymorphous Light Eruption
Polymorphous light eruption, often called sun allergy, is a common condition in which the skin develops an itchy rash of red bumps, blisters, or patches hours to days after sun exposure, usually because skin hasn't adjusted to UV light after winter. Among supplements, beta-carotene, vitamin D, nicotinamide, and Polypodium leucotomos have drawn the most interest, but little research on them has been reviewed here so far. Because no trial findings are available to report, it's too early to say how well any of them work for this rash.
- Best evidence:
Postdural Puncture Headache
Postdural puncture headache follows a spinal tap, spinal anesthesia, or epidural, when a small hole in the membrane around the spinal cord leaks fluid, lowers pressure, and brings pain that eases lying down. Caffeine has the most research behind it, and one small trial of 94 people having spinal anesthesia for cesarean delivery found fewer headaches when it was paired with acetaminophen. Since that is a single study, the evidence is limited.
- Best evidence:
Prader-Willi Syndrome (PWS)
Prader-Willi syndrome is a genetic condition caused by missing or inactive genes on chromosome 15, affecting about 1 in 15,000 births and touching appetite, muscle tone, growth, and bone health. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report. Vitamin D and calcium are the most discussed because bone thinning is common, but that rests on their general role in bone health rather than on results in people with this condition.
- Best evidence:
Purine Metabolism
Purine metabolism is how the body makes and breaks down purines, the building blocks of DNA and RNA, with the enzyme xanthine oxidase helping turn them into uric acid. Molybdenum, a mineral that enzyme relies on, has moderate evidence, and studies found xanthine oxidase activity went up. That rests on about 150 participants and measured the enzyme itself, so it says little yet about uric acid or how people felt.
- Best evidence:
Renal Colic
Renal colic is the severe pain that comes when a kidney stone moves through the urinary tract and blocks urine flow. Little research on supplements for it has been reviewed here so far, so there are no findings to report yet. The acute episode usually needs medical care, and since about half of stone formers form another stone within 5 to 10 years, the stone type shapes what matters afterward.
- Best evidence:
Rett Syndrome (RTT)
Rett syndrome is a rare genetic disorder, caused by changes in the MECP2 gene, in which girls who seem to develop normally for the first year or so lose skills such as purposeful hand use and speech. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Vitamin D, melatonin and calcium are the names that come up most, mainly for bone health and sleep, but that interest rests on how they work in the body rather than on results in Rett syndrome.
- Best evidence:
Rosacea
Rosacea is a long-lasting condition in which the blood vessels and skin of the face become inflamed, often set off by stress, environmental factors and gut imbalances. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Zinc is the one supplement in view, valued for possible anti-inflammatory and skin-barrier effects, though the evidence is very limited.
- Best evidence:
Sleep Terrors
Sleep terrors are episodes of screaming, intense fear and thrashing during sleep, most common in children and usually outgrown by adolescence. Among supplements, 5-HTP has the most direct research: in one study of 45 children, sleep terrors became less frequent. That was a single small study, so the evidence is limited, as it is for magnesium, vitamin D and melatonin.
- Best evidence:
Spinal Cord Injury
A spinal cord injury is damage to the nerves running through the spine, which causes paralysis and loss of sensation below the injury and can affect bones, bowel, bladder, circulation and skin. Vitamin D and calcium are the supplements most often looked at, mainly for the rapid bone loss that follows injury. Little research on them in this condition has been reviewed here so far, so no trial findings can be reported yet.
- Best evidence:
Telangiectasia (Spider Veins)
Telangiectasia, often called spider veins, is a widening of tiny blood vessels near the skin's surface that shows up as thin red, purple, or blue lines, and it is usually a cosmetic concern. People most often look at horse chestnut extract and hesperidin/diosmin, which are rated as having moderate evidence, though little research on spider veins specifically has been reviewed here so far. Vitamin C, grape seed extract, bilberry, gotu kola, and rutin have even less behind them, so the evidence there is limited.
- Best evidence:
Thyroid Cancer
Thyroid cancer starts when cells in the thyroid, the butterfly-shaped gland in the neck that helps set your metabolism, begin growing out of control. Little research on supplements for it has been reviewed here so far, though selenium and vitamin D have the most supporting material, with a moderate evidence rating. Much of the case for them rests on how they work in the body, and for others like curcumin and green tea extract, the findings come mostly from lab studies.
- Best evidence:
Tuberous Sclerosis Complex (TSD)
Tuberous sclerosis complex is a rare genetic condition in which faulty growth-control genes let non-cancerous tumors form in the brain, kidneys, heart, lungs, eyes, and skin. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report. Cannabidiol has the strongest backing, since a prescription form is approved for its seizures, while the evidence for vitamin D, omega-3s, folate, and calcium is limited.
- Best evidence:
Venous Hypertension
Venous hypertension is abnormally high pressure in the leg veins, usually because faulty valves let blood flow backward and pool in the legs, a pattern known as chronic venous insufficiency. Horse chestnut extract and diosmin/hesperidin are the two supplements with the strongest evidence behind them for this condition. Little research on either has been reviewed here so far, though, so there are no trial findings to report yet, and the other supplements people try have less support still.
- Best evidence:
Venous Thromboembolism (Blood Clotting)
Venous thromboembolism is a blood clot that forms in a deep vein, usually in the leg, and can break loose and travel to the lungs, where it blocks blood flow. Omega-3 fatty acids and vitamin D are the supplements people look at most, but little research on them for this condition has been reviewed here so far. Their mild effects on platelets and clotting are plausible on paper, yet no trial findings can be reported, so the evidence is too thin to say whether they matter.
- Best evidence:
Warts
Warts are benign skin growths caused by an infection with human papillomavirus (HPV), and they are very common. They are usually harmless, though they can be bothersome or uncomfortable. People often look at zinc, along with echinacea, vitamin A and vitamin C, for immune support, but little research on them has been reviewed here so far. The evidence is moderate for zinc and limited for the others, so firm conclusions are still out of reach.
- Best evidence:
Wheelchair Athletic Performance
Wheelchair athletics covers sports such as racing, basketball, tennis and rugby, where performance leans mainly on upper body strength and cardiovascular conditioning. Caffeine and whey protein have the strongest backing in the supplement literature for athletes like these, with creatine also looked at for upper body power. Little research on any of them in wheelchair athletes has been reviewed here so far, so it's too early to say what trials found for this group.
- Best evidence:
Liver Fibrosis
Liver fibrosis is a buildup of scar tissue in the liver, which happens when long-term injury or inflammation switches on stellate cells that lay down too much of the fibrous material between liver cells. Among supplements, TB-500, a synthetic version of a thymosin beta 4 fragment, has the most to show so far, and lab models found it calmed those stellate cells and reduced scar-tissue buildup. The evidence is limited, though, because the work was mostly in animals or cell studies, so it says little yet about what happens in people.
- Best evidence:
Ligament Injury
Damage to ligaments and tendons requiring healing
- Best evidence:
Neurodegeneration
Neurodegeneration is the gradual loss of nerve cells and their connections in the brain and spinal cord, as seen in conditions like Alzheimer's disease. Among supplements, TB-500, a peptide related to thymosin beta-4, has drawn attention, and preclinical studies found it lessened neuronal damage and helped neural stem cells migrate. The evidence is very limited, though, because the work was small and mostly in animals or lab studies.
- Best evidence:
Hair Growth
Hair growth is the cycle in which follicles in the scalp build new hair, rest, shed it and start again, and it is steered by stem cells and signals within each follicle. Among supplements, TB-500 is the one with reviewed research, and the evidence is very limited: studies found it stimulated follicle stem cells and promoted hair growth in animals. Those studies were small and mostly animal or lab work, so they say little yet about what it might do for people.
- Best evidence:
Abdominal Aortic Aneurysm
An abdominal aortic aneurysm is a bulge in the aorta, the body's main blood vessel, where a weakened wall stretches and can slowly enlarge, and if it ruptures it is a life-threatening emergency. Little research on supplements for it has been reviewed here so far, though omega-3s and vitamin D draw the most interest. Low vitamin D was linked to larger aneurysms in observational work, which cannot show that supplementing changes anything.
- Best evidence:
Anorexia Nervosa
Anorexia nervosa is a serious eating disorder marked by severe food restriction, an intense fear of gaining weight, and a distorted body image, and long-term starvation strains the heart, bones, brain, hormones, and immune system. Zinc and a multivitamin-mineral supplement are the ones most often looked at, but little research on them has been reviewed here so far. Because there are no findings to report yet, it is too soon to say what any supplement does for people with this condition.
- Best evidence:
Aplastic Anemia
Aplastic anemia is a rare, serious condition in which the bone marrow stops making enough red cells, white cells and platelets, leaving people tired, short of breath, prone to infections and quick to bleed. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report. Vitamin D and a multivitamin are the most often discussed, but the evidence for each is limited, and medical treatment remains the core of care.
- Best evidence:
Autoimmune Hepatitis
Autoimmune hepatitis is a long-lasting liver disease in which the immune system mistakenly attacks liver cells, causing inflammation that can lead to scarring. Little research on supplements for it has been reviewed here so far, and the one trial on hand tested vitamin E in a different liver condition, fatty liver inflammation. Interest in vitamin D and omega-3s rests mostly on their immune and anti-inflammatory roles, so the evidence is limited.
- Best evidence:
Avoidant Restrictive Food Intake Disorder
Avoidant restrictive food intake disorder, or ARFID, is an eating disorder in which someone eats very little or a narrow range of foods because of low interest in eating, sensitivity to texture, taste or smell, or fear of choking or vomiting, not because of body image worries. Little research on supplements for it has been reviewed here so far. Multivitamin and mineral products, vitamin D, iron, zinc and calcium come up most often.
- Best evidence:
Basal Cell Carcinoma
Basal cell carcinoma is the most common skin cancer, starting in basal cells of the skin's outer layer after years of UV exposure and often appearing as a pearly bump or a sore that lingers. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Nicotinamide, a form of vitamin B3, has the strongest evidence among options people discuss, followed by vitamin D.
- Best evidence:
Baseball Performance
Baseball performance is the blend of explosive power for hitting and throwing, split-second reactions, and recovery from game to game across a long season. Creatine and caffeine have the strongest evidence among supplements people look at for it, though little research on baseball itself has been reviewed here so far. The others, like tart cherry and beta-alanine, have moderate evidence at best, and results from other sports may not carry over.
- Best evidence:
Behcet's Disease
Behcet's disease is a rare, long-lasting inflammatory condition in which blood vessels throughout the body become inflamed, most often causing painful mouth and genital ulcers and eye inflammation, and sometimes affecting joints, skin, gut, or brain. Among supplements, vitamin D and omega-3 fatty acids have the most support, though little research on them has been reviewed here so far. Any findings should be read cautiously until larger, well-designed trials in people with Behcet's are available.
- Best evidence:
Body Dysmorphic Disorder
Body dysmorphic disorder is a mental health condition where a person fixates on appearance flaws that are minor or unseen by others, causing real distress and disrupting daily life. Little research on supplements for it has been reviewed here so far. NAC and omega-3s draw the most interest, with moderate evidence at best, while the one review available, on L-theanine for anxiety, was limited.
- Best evidence:
Brain Cancer
Brain cancer is a group of tumors that either start in the brain or spread there from elsewhere, and the most common aggressive type, glioblastoma, tends to keep growing despite treatment. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Boswellia has the most support of the options studied, with moderate evidence tied to easing brain swelling after radiation, while omega-3s and vitamin D have only limited evidence.
- Best evidence:
Bruxism
Bruxism is a condition characterized by excessive grinding of the teeth or clenching of the jaw, while awake or sleeping.
- Best evidence:
Bulimia Nervosa
Bulimia nervosa is a serious eating disorder of binge eating followed by purging, fasting, or overexercising, and vomiting or laxatives can drain the body of fluids and minerals like potassium. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report. Electrolytes and a multivitamin come up most, but that rests on how purging affects nutrient levels, not on trial results.
- Best evidence:
Caffeine Addiction
Caffeine addiction is a dependence that builds with regular use, as the body adapts and needs more for the same effect, then reacts to stopping with withdrawal. Little research on supplements for it has been reviewed here so far, though people most often look at L-theanine and magnesium. The L-theanine studies covered anxiety and stress generally rather than caffeine withdrawal, so how well it helps here remains unclear.
- Best evidence:
Cashew Allergy
Cashew allergy is an immune reaction in which the body makes IgE antibodies against proteins in cashews, triggering symptoms from hives and stomach upset to severe anaphylaxis. Vitamin D and probiotics are the supplements most often looked at alongside it, but little research on them for this allergy has been reviewed here so far. Cashews are closely related to pistachios, so people with this allergy are often allergic to both.
- Best evidence:
Cellulite
Cellulite is a common, harmless skin condition that causes lumpy, dimpled flesh on the thighs, hips, buttocks, and abdomen, appearing when fat cells push up against the skin while fibrous bands beneath pull down. It affects most women after puberty and far fewer men. Little research on supplements for cellulite has been reviewed here so far, so it is too early to say what the trials found for any of them.
- Best evidence:
Cervical Cancer
Cervical cancer starts in the cells of the cervix, the lower part of the uterus, and is almost always driven by a long-lasting infection with high-risk strains of human papillomavirus (HPV). Little research on supplements for cervical cancer has been reviewed here so far, so there are no trial findings to report yet. Vitamin D, probiotics and ginger have drawn the most interest, but that interest rests on how they might work, not on results.
- Best evidence:
Cold Hypersensitivity
Cold hypersensitivity, also called cold intolerance, means feeling uncomfortably cold when others are comfortable, or having hands and feet that stay cold, and it can point to an underlying issue such as low iron or poor circulation. Ginkgo biloba and omega-3 fatty acids are the supplements people look at most, though little research on them for this has been reviewed here so far. Iron and vitamin B12 matter mainly when a shortfall is behind the chill, so the cause is worth understanding first.
- Best evidence:
Complex Regional Pain Syndrome
Complex regional pain syndrome is a chronic pain condition that usually affects one limb after an injury or surgery, with pain far out of proportion to the original harm, along with changes in skin color, temperature, swelling, and movement. Among supplements, vitamin C has the strongest evidence, though little research on it has been reviewed here so far. Alpha-lipoic acid and topical DMSO have moderate evidence at best, and the rest is limited.
- Best evidence:
Cystitis
Cystitis is inflammation of the bladder, most often caused by a bacterial infection such as E. coli that irritates the bladder lining and brings pain, urgency and burning. People most often look at D-mannose and cranberry, but little research on them has been reviewed here so far. For now, it is too early to say how well any supplement works for it.
- Best evidence:
Dandruff
Dandruff is a common scalp condition in which skin cells flake off in visible white or yellowish scales, often with itching, linked to an overgrowth of a yeast that naturally lives on the scalp and to the way the skin reacts to it. Little research on supplements for dandruff has been reviewed here so far, so there are no findings to report yet. Because that work is still thin, it says little about whether nutrition plays a role.
- Best evidence:
Delayed Sleep Wake Phase Disorder
Delayed sleep-wake phase disorder is a condition where the body's internal clock runs hours late, so people fall asleep very late and wake late, though their sleep itself is normal. Melatonin and morning bright light have the strongest evidence for shifting the clock earlier, though little research on them has been reviewed so far. Magnesium and L-theanine have only limited evidence, and the condition is most common in teens and young adults.
- Best evidence:
Diaper Rash
Diaper rash is irritated skin under the diaper, common in babies, brought on by lasting contact with urine and stool, friction, and warm, moist conditions. The evidence is strongest for zinc oxide and petrolatum barrier products, though little research on them has been reviewed here so far. Probiotics and calendula have moderate evidence, while aloe vera, which one review covered for skin conditions, is limited.
- Best evidence:
Disordered Eating
Disordered eating is a range of unhealthy eating behaviors that fall short of a formal eating disorder diagnosis, spanning occasional habits to conditions like anorexia, bulimia, and binge eating disorder. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Zinc and omega-3 fatty acids come up most often, since restrictive eating can leave nutrient gaps.
- Best evidence:
Down Syndrome
Down syndrome is a genetic condition caused by an extra copy of chromosome 21, which shapes physical and cognitive development and is linked with certain health conditions. Vitamin D and omega-3 fatty acids are the supplements people look at most, but little research on them has been reviewed here so far. Interest rests on reasoning, such as low vitamin D and zinc levels being common, so it is too early to say what they do.
- Best evidence:
Dyslexia
Dyslexia is a learning difference that affects reading, spelling, and writing, rooted in how the brain processes written language, and it has nothing to do with intelligence. Omega-3 fatty acids and vitamin D are the supplements most often looked at, but little research on them has been reviewed here so far. Even the ideas behind them, such as supporting brain development, rest on limited evidence, so no supplement has a clear track record for dyslexia.
- Best evidence:
Egg Allergy
Egg allergy is an immune reaction to proteins in egg, mostly those in the white, and it causes symptoms from hives and an upset stomach to severe anaphylaxis. Vitamin D and probiotics are the supplements people look at most, but little research on them for egg allergy has been reviewed here so far. Most children outgrow it by adolescence, and many can tolerate baked egg because heat alters the proteins.
- Best evidence:
Ehlers-Danlos Syndrome
Ehlers-Danlos syndrome is a group of inherited conditions caused by defects in collagen and other connective tissue proteins, leaving joints and skin more fragile or stretchy. People often look at vitamin C and magnesium for connective tissue support and muscle pain, but little research on them has been reviewed here so far. The evidence is limited, and their appeal rests mostly on how they work in the body, not on trial results.
- Best evidence:
End of Life
End of life is the final stage of a serious illness, when care turns toward comfort and the body often brings pain, nausea, fatigue, poor sleep, anxiety and loss of appetite. Among supplements, omega-3 fatty acids and vitamin D are the ones people look at most, but little research on them for this stage has been reviewed here so far. So it is too early to say how well any of them work.
- Best evidence:
Endometrial Cancer
Endometrial cancer begins in the lining of the uterus, called the endometrium, and it is the most common gynecological cancer in developed countries, with most cases arising after menopause. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Vitamin D, omega-3 fatty acids, protein and ginger get the most attention, but the case for each rests mainly on how they might work, not on results in this cancer.
- Best evidence:
Esophageal Cancer
Esophageal cancer is a serious cancer of the esophagus, the tube that carries food from the throat to the stomach, and it comes in two main forms: squamous cell carcinoma and adenocarcinoma. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Any supplement question is best talked through with a cancer care team, since treatment often affects eating, weight and nausea.
- Best evidence:
Fecal Incontinence
Fecal incontinence is the involuntary loss of stool or gas, often from weak pelvic floor muscles, nerve damage, loose stools, or constipation with overflow. Little research on supplements for it has been reviewed here so far. Psyllium fiber is the one most often discussed, since it bulks stool and may make it firmer, but that idea rests mainly on how it works rather than on trial results.
- Best evidence:
Food addiction
Food addiction is a pattern in which highly processed foods, rich in sugar, fat and salt, seem to set off addiction-like responses in the brain's reward system, and it is often identified with the Yale Food Addiction Scale. Among supplements, NAC and omega-3 fatty acids are the ones most often studied for it, but little research on them for this pattern has been reviewed here so far. The idea is still debated, so it is too early to say whether any supplement helps.
- Best evidence:
Gastritis
Gastritis is inflammation of the stomach lining, either arriving suddenly or building gradually over time, often linked to H. pylori infection or irritants that wear down the stomach's protective layer. People most often look at probiotics and zinc-L-carnosine, though little research on supplements for gastritis has been reviewed here so far. The evidence for both is moderate at best, and it is limited for DGL and mastic gum.
- Best evidence:
Gastrointestinal Tract Infection
Gastroenteritis is an infection by a virus, bacterium, or parasite that inflames the stomach and intestines, causing diarrhea and vomiting that can leave the body short of fluid. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Oral rehydration salts, probiotics, and zinc have the strongest evidence overall.
- Best evidence:
Graves' Orbitopathy
Graves' orbitopathy, also called thyroid eye disease, is an autoimmune condition in which the immune system attacks the muscles and tissues around the eyes, causing swelling and irritation, and it usually appears alongside an overactive thyroid. Selenium has the strongest evidence among supplements, with vitamin D, omega-3 fatty acids and antioxidant blends trailing behind at limited. Little research on any of them has been reviewed here so far, so it is too early to say what trials found.
- Best evidence:
Hookworm
Hookworm infection comes from parasitic worms that live in the soil, enter through the skin (often bare feet), and settle in the intestines, where they attach to the gut lining and feed on blood. Among supplements, iron has the strongest case because the ongoing blood loss can leave people short of iron and anemic, but little research on it has been reviewed here so far. Folate, vitamin B12, vitamin A, zinc and vitamin C have a more modest case, mostly for supporting recovery from anemia and immune function.
- Best evidence:
Hot Flashes
Hot flashes are sudden waves of warmth, most intense over the face, neck, and chest, caused by changes in the body's temperature-control system as estrogen declines during menopause. Black cohosh and soy-type isoflavones are the supplements with the strongest evidence, rated moderate, but little research on them has been reviewed here so far. Other options such as evening primrose oil, sage, and flaxseed have only limited evidence behind them.
- Best evidence:
Hypermobility
Hypermobility is a condition in which joints move easily beyond the normal range, often because the connective tissue that holds them together is looser than usual, and while it can be harmless, for many people it brings pain and instability. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Vitamin C and collagen come up most often because both relate to how connective tissue is built, but that rests on their roles in the body rather than on results in people with hypermobility.
- Best evidence:
Hyperprolactinemia
Hyperprolactinemia is a state of too much prolactin, a pituitary hormone that drives breast milk production and also influences reproductive function, so it can bring irregular or absent periods, infertility, breast discharge, or low libido. Little research on supplements for it has been reviewed here so far. Vitex has the strongest support of those considered, rated moderate, while vitamin B6 is limited and maca and ashwagandha are very limited.
- Best evidence:
Idiopathic Axonal Polyneuropathy
Idiopathic axonal polyneuropathy is damage to the nerve fibers themselves across several nerves, with no cause found despite thorough testing, and it usually brings numbness, tingling or burning that starts in the feet and creeps upward. Alpha-lipoic acid and vitamin B12 are the supplements most often studied for it, but little research on them for this condition has been reviewed here so far. Because of that, it is hard to say how well any supplement works for this particular kind of neuropathy.
- Best evidence:
Internet Addiction Disorder
Internet addiction disorder is a pattern of excessive internet use that gets in the way of daily life, relationships, and responsibilities, and it shares features with other behavioral addictions. Little research on supplements for it has been reviewed here so far, though N-acetyl cysteine and omega-3 fatty acids are the main ones studied. The evidence for every supplement considered is limited, so it is too early to say whether any makes a real difference.
- Best evidence:
Internet Gaming Disorder
Internet Gaming Disorder is a pattern of gaming in which a person loses control over play, puts it ahead of other parts of life, and keeps going despite clear harm. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. N-acetyl cysteine and omega-3 fatty acids are the ones most often studied, but the evidence is limited.
- Best evidence:
Intestinal Candidiasis
Intestinal candidiasis is an overgrowth of Candida, a yeast that normally lives in the gut in small amounts, when something tips the balance and it multiplies, sometimes bringing digestive symptoms. Probiotics, including the yeast Saccharomyces boulardii and Lactobacillus strains, are the supplements people look at most, though little research on them for this condition has been reviewed here so far. Caprylic acid, oregano oil, garlic extract and berberine are also used, but the evidence for them is limited.
- Best evidence:
Kidney Cancer
Kidney cancer, or renal cell carcinoma, begins when cells in the kidney grow out of control, and it is often found by chance on scans done for other reasons. Little research on supplements for it has been reviewed here so far. Vitamin D, omega-3s and protein are the main ones explored as supportive care, and the evidence is limited to moderate at best, so it remains early.
- Best evidence:
Klinefelter Syndrome
Klinefelter syndrome is a genetic condition in males caused by an extra X chromosome, which often means lower testosterone and a range of physical, developmental, and hormonal differences. Vitamin D and calcium are the supplements most often discussed, mainly for bone health, but little research on them in this condition has been reviewed here so far. Omega-3s, zinc, and magnesium come up too, and the evidence for them is limited.
- Best evidence:
Lead Poisoning
Lead poisoning happens when lead slowly builds up in the body and harms the nervous system, and even low levels can cause serious problems, especially in children. Little research on supplements for it has been reviewed here so far. Calcium and iron have the most support, with moderate evidence, since enough calcium may limit lead absorption and low iron may increase it, while vitamin C, zinc and vitamin D have limited evidence.
- Best evidence:
Learning Disability
Learning disabilities are neurological differences in how the brain processes information, affecting skills such as reading, writing or math, and they are not a sign of low intelligence. Little research on supplements for them has been reviewed here so far, though one systematic review looked at vitamin D and neurodevelopment. Iron and omega-3 fatty acids get the most attention, mainly for children who are low in them, so the picture is still early.
- Best evidence:
Lipedema
Lipedema is a chronic fat disorder, almost only in women, where painful fat builds up symmetrically in the legs, and sometimes arms, out of proportion to the rest of the body. Little research on supplements for it has been reviewed here so far, and the evidence for omega-3s, selenium and vitamin D is limited. It often starts around puberty, pregnancy or menopause, which hints at hormones.
- Best evidence:
Maple Syrup Urine Disease
Maple syrup urine disease is a rare inherited disorder in which the body cannot properly break down the amino acids leucine, isoleucine and valine, so they and their toxic byproducts build up. Little research on supplements for it has been reviewed here so far, though a BCAA-free medical formula and thiamine are the main options discussed. Thiamine is thought to help only in thiamine-responsive variants, while carnitine, vitamin D and calcium play supporting roles.
- Best evidence:
Mastitis
Mastitis is a painful inflammation of breast tissue, most often in breastfeeding women, where blocked milk flow or infection leaves the breast swollen, tender and sore. Probiotics, especially Lactobacillus strains, are the supplements people look at most, and the evidence for them is moderate, though little research on mastitis itself has been reviewed here so far. Lecithin, vitamin C, vitamin D and omega-3s have only limited evidence, so their role is still uncertain.
- Best evidence:
Mouth Cancer
Mouth cancer starts in the cells lining the lips, tongue, cheeks, floor of the mouth, palate or gums, and most cases are squamous cell carcinomas, where surface cells grow abnormally. Little research on supplements for it has been reviewed here so far. Glutamine and protein are mostly of interest for easing mouth sores and keeping up nutrition during treatment, not for the cancer itself.
- Best evidence:
Myelodysplastic Syndrome
Myelodysplastic syndromes are bone marrow disorders in which the marrow makes abnormal, poorly working blood cells, leaving people with low red cells, white cells and platelets, which brings fatigue, infections and bleeding risk. Little research on supplements for this condition has been reviewed here so far, so there are no trial findings to report. Vitamin D, omega-3s, B12 and folate come up most often, but their role in MDS rests mainly on how they support the body in general, so it is worth talking with a hematology team about any of them.
- Best evidence:
Myeloid Malignancies
Myeloid malignancies are blood cancers that begin in myeloid cells in the bone marrow, the cells that normally mature into red blood cells, platelets and several kinds of white blood cells. Little research on supplements for these cancers has been reviewed here so far, so there are no trial findings to report yet. Vitamin D and omega-3 fatty acids are the most often discussed, but that rests on their proposed roles in immune function and inflammation rather than on results in people with these cancers.
- Best evidence:
Myopia
Myopia, or nearsightedness, happens when the eye grows too long, so distant objects look blurry while close ones stay clear. It usually starts in childhood and progresses through the teen years. Vitamin D and omega-3 fatty acids are the supplements most often discussed for it, but little research on their effects has been reviewed here so far. Much of the interest in vitamin D comes from outdoor light exposure, which is linked to slower progression.
- Best evidence:
Myositis
Myositis is a group of rare conditions in which the immune system drives long-lasting inflammation in the muscles, causing weakness; the main types are dermatomyositis, polymyositis, and inclusion body myositis. Vitamin D and creatine are the supplements most often discussed for it, but little research on them in myositis has been reviewed here so far. Because of that, it is too early to say how much either one helps people living with the condition.
- Best evidence:
Nail Fungus
Nail fungus, or onychomycosis, is an infection in which fungi invade the nail, most often on the toes, leaving it thick, discolored and brittle. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report for options such as topical tea tree oil or biotin. Both have been discussed for nail health, but the evidence is limited, and it isn't yet clear how well any supplement works for the infection itself.
- Best evidence:
Orthorexia Nervosa
Orthorexia nervosa is an unhealthy preoccupation with eating pure or healthy food, focused on food quality rather than weight loss, and it can lead to nutritional gaps, social isolation, and distress. Little research on supplements for it has been reviewed here so far, so there are no findings to report. Omega-3s, B vitamins, and zinc come up because strict food rules can leave nutrients low, but that is reasoning, not proof of benefit.
- Best evidence:
Penile Cancer
Penile cancer is a rare cancer that starts in the skin or tissues of the penis, where cells grow out of control. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report. Vitamin D, omega-3s, zinc, selenium and protein are of interest for immune and nutritional support, but that rests on how they work, not on studies in this cancer.
- Best evidence:
Portal Hypertension
Portal hypertension is raised pressure in the portal vein, which carries blood from the intestines to the liver, usually because cirrhosis scarring makes blood hard to push through. There is little research on supplements for it so far, though branched-chain amino acids and zinc have the most behind them, rated moderate. Both matter because people with liver disease are often low in them, but what they do for the pressure itself remains unclear.
- Best evidence:
Primary Ovarian Insufficiency
Primary ovarian insufficiency is a condition in which the ovaries stop working normally before age 40, so periods become irregular, estrogen runs low, and getting pregnant is often harder. Among supplements, vitamin D and calcium are the ones most often discussed, mainly for bone health, but little research on them in this condition has been reviewed here so far. Because low estrogen speeds bone loss, that link makes sense, yet it isn't a finding from trials in women with this condition.
- Best evidence:
Psoriatic Arthritis
Psoriatic arthritis is an inflammatory arthritis in which an overactive immune system attacks the joints, causing pain, stiffness and swelling, and sometimes swollen fingers or toes and nail changes. So far, little research on supplements for it has been reviewed. Omega-3 fatty acids and vitamin D draw the most interest because of their roles in inflammation and immune balance, but it's too early to say how well any supplement works.
- Best evidence:
Reactive Hypoglycemia
Reactive hypoglycemia is low blood sugar that shows up two to four hours after a meal, usually a carbohydrate-heavy one, when the body releases too much insulin and blood sugar drops too far, bringing shakiness, sweating, and hunger. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Fiber and chromium are the ones most often discussed, but their effects on this condition remain untested in the studies covered.
- Best evidence:
Relative Energy Deficiency in Sport (RED-S)
Relative Energy Deficiency in Sport (RED-S) happens when an athlete's food intake falls short of what training and basic body functions need, so the body starts dialing down reproductive hormones, bone building, metabolism, and eventually heart and mental health. People often look at vitamin D and calcium for it, given their role in bone health, but little research on them in this setting has been reviewed here so far. Nothing here yet shows how well any supplement works for RED-S, so eating enough remains the central issue.
- Best evidence:
Reproductive Tract Infections (RTIs)
Reproductive tract infections are infections of the female or male reproductive system, from common vaginal infections to sexually transmitted infections, often linked to a shift in the balance of microbes. Little research on supplements for them has been reviewed here so far, so there are no trial findings to report yet. Probiotics and vitamin D are the main candidates people look at, given their roles in supporting vaginal flora and immune defenses.
- Best evidence:
Respiratory Distress Syndrome
Acute respiratory distress syndrome is a severe lung condition in which the lungs become inflamed and fill with fluid, making breathing very hard, and it usually follows serious illness such as pneumonia, sepsis, trauma, or aspiration. Omega-3 fatty acids and intravenous vitamin C have drawn the most interest among supplements, but little research on them has been reviewed here so far. Care happens in intensive care with mechanical ventilation, and nutrition is only a supporting piece.
- Best evidence:
Retinopathy of Prematurity
Retinopathy of prematurity is an eye disease of babies born very early, in which the retina's blood vessels haven't finished growing, and the abnormal vessels that follow can cause scarring, retinal detachment, and even blindness. Omega-3 fatty acids (DHA) and vitamin E are the supplements most often studied for it. Little research on either has been reviewed here so far, so no findings can be reported yet. Anything beyond that is still an open question.
- Best evidence:
Scleroderma
Scleroderma, also called systemic sclerosis, is a rare autoimmune disease in which the immune system drives hardening and thickening of the skin and connective tissue, sometimes reaching the lungs, heart, kidneys, and gut. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Vitamin D and omega-3 fatty acids draw the most interest, with moderate evidence for vitamin D and limited for omega-3.
- Best evidence:
Sexually Transmitted Infections (STIs)
Sexually transmitted infections are infections passed on through sexual contact, caused by bacteria, viruses or parasites that take hold in the genital tract, mouth or bloodstream and need a medical diagnosis. Zinc and vitamin D are the supplements most often discussed alongside them, largely for their part in immune function, but little research on them has been reviewed here so far. Any evidence that exists is limited, so these are not substitutes for proper testing and care.
- Best evidence:
Sleep Paralysis
Sleep paralysis is a brief spell when you wake up or drift off fully aware but unable to move or speak, because the body's muscle shutdown during dreaming sleep lingers a little too long. It is frightening but generally harmless. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet.
- Best evidence:
Small Intestinal Bacterial Overgrowth (SIBO)
Small intestinal bacterial overgrowth, or SIBO, happens when unusually large numbers of bacteria settle in the small intestine, where they ferment food early and can cause bloating, gas, discomfort and loose stools. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Careful studies are still needed before anyone can say whether any supplement makes a real difference.
- Best evidence:
Sport Climbing Performance
Sport climbing performance depends on grip strength, endurance and focus, and forearm pump, when the forearms tire before the rest of the body, is a classic limiter. Creatine, beta-alanine and caffeine have the strongest evidence among the supplements climbers look at, though little climbing-specific research has been reviewed so far. Citrulline, beetroot juice and tart cherry have moderate evidence, and how well any of them work for climbers remains unclear.
- Best evidence:
Stomach Cancer
Stomach cancer is a cancer that starts in the cells lining the stomach, where abnormal growth can interfere with digestion and, after surgery, with how the body takes in nutrients. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Omega-3 fatty acids and vitamin D have drawn the most interest, though the evidence for both is limited, and B12 matters because the body cannot absorb it well after the stomach is removed.
- Best evidence:
Sunburn
Sunburn is skin damage caused by ultraviolet radiation, usually from the sun, which inflames the skin so it turns red and sore and, in severe cases, blisters. People most often look at topical aloe vera and vitamin C to soothe it, though little research on either has been reviewed here so far. Vitamin E, omega-3 fatty acids and zinc come up too, but the science behind all of these is still early.
- Best evidence:
Takayasu's Arteritis
Takayasu's arteritis is a rare inflammatory disease in which the walls of the aorta and its major branches thicken and narrow, limiting blood flow to organs and limbs. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report. Vitamin D and calcium come up most, for bone health during steroid treatment, but that rests on how they work, not on trials in this condition.
- Best evidence:
Teratozoospermia
Teratozoospermia is a condition in which a large share of a man's sperm have abnormal shapes, such as misshapen heads or double tails, which can make it harder for them to swim to and fertilize an egg. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Zinc and coenzyme Q10 are the most often discussed, and men with abnormal sperm shape can still father children, especially with assisted reproduction.
- Best evidence:
Testicular Cancer
Testicular cancer starts in the cells of a testicle, most often in young men between about 15 and 35, and is usually managed with surgery, sometimes followed by chemotherapy or radiation. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report. Ginger, for chemotherapy nausea, and vitamin D have the most backing among supplements, though that evidence is only moderate.
- Best evidence:
Tonsillitis
Tonsillitis is inflammation of the tonsils, the two lymph-tissue pads at the back of the throat, usually set off by a viral or bacterial infection that brings a sore throat, painful swallowing, and swollen glands. Vitamin C and zinc are the supplements people look at most, but little research on them for tonsillitis itself has been reviewed here so far. Probiotics, vitamin D, and elderberry have even less behind them, so it is too early to say how much any of them helps.
- Best evidence:
Tree Nut Allergy
Tree nut allergy is an immune reaction in which the body makes IgE antibodies against proteins in nuts such as almonds, cashews, walnuts and pistachios, and it can trigger severe, life-threatening reactions. Probiotics, vitamin D and omega-3 fatty acids have all been looked at because of their possible effects on the immune system, but little research on them for this allergy has been reviewed here so far. The evidence for each is limited, so none can be pointed to as a clear help.
- Best evidence:
Urethral Gland Cancer
Urethral cancer is a rare cancer that starts in the urethra, the tube carrying urine from the bladder out of the body, and it is more common in women than in men. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report. Ideas such as vitamin D, omega-3s and protein come from their general roles in supporting nutrition and immune function during cancer care, not from studies of this cancer.
- Best evidence:
Urinary Tract Infection
A urinary tract infection happens when bacteria, most often E. coli, cling to the lining of the bladder and multiply, causing burning, urgency and sometimes reaching the kidneys. Cranberry and D-mannose are the supplements most often discussed for keeping bacteria from sticking to the bladder wall, but little research on them has been reviewed here so far. Until more studies are added, it is too early to say how well any supplement works.
- Best evidence:
Urination Problems
Urination problems, known as lower urinary tract symptoms, include a weak stream, urgency, frequent trips and waking at night, and in men they often come from an enlarged prostate squeezing the urethra. The evidence looks strongest for beta-sitosterol and moderate for saw palmetto, though little research on them has been reviewed here so far. Both are used for prostate enlargement, so they may matter less for women, whose causes often differ.
- Best evidence:
Urticaria
Urticaria, or hives, is a skin condition of itchy, raised, red welts that appear when skin cells release histamine and other chemicals. Vitamin D and probiotics are the supplements most often looked at, but little research on them has been reviewed here so far. Any early signs are tentative, since the evidence is moderate for vitamin D and limited for probiotics, and it is limited for the others too.
- Best evidence:
Ventilator-Associated Pneumonia
Ventilator-associated pneumonia is a lung infection that develops in people on a breathing machine, usually more than two days after the tube is placed, when bacteria from the mouth, sinuses, or stomach slip into the lungs. Little research on supplements for it has been reviewed here so far, so there are no trial findings to report yet. Probiotics and vitamin D have drawn the most interest, but that interest rests mainly on how they might work, not on results.
- Best evidence:
Wounds and burns
A wound is damage to skin or deeper tissue from surgery, injury, or a burn, which the body rebuilds using extra nutrients. Vitamin C, zinc, and protein are the nutrients most often studied for supporting repair, but little research on them has been reviewed here so far. One systematic review did look at aloe vera on burns, so the picture is still thin.
- Best evidence:
Xerosis
Xerosis, or dry skin, happens when the outer layer of the skin lacks enough moisture and natural oils, leaving it rough, flaky, tight and sometimes itchy. Omega-3 fatty acids and vitamin E are the supplements most often linked to it, and the evidence is rated strong for omega-3s and moderate for vitamin E. Little research on xerosis itself has been reviewed here so far, so no specific trial findings can be reported yet.