Supplements
554 supplements, each graded A to D on the strength of the clinical evidence.
Supplement list
- Best evidence:
L-Carnitine
L-Carnitine is a compound made from amino acids that carries fatty acids into the mitochondria, the cell's energy producers, so they can be burned for fuel. People mostly look at it for prediabetes, and the evidence is moderate: several trials found blood glucose improved. Those studies were small in effect, though, and the findings mostly come from pooled analyses of trials, so they don't show how it works for any one person.
- Best evidence:
Curcumin
Curcumin is the yellow pigment in turmeric, and in the body it works as an antioxidant and calms inflammatory signaling. People most often look at it for oral mucositis, the painful mouth inflammation that can follow cancer treatment, and the evidence is strong: mucositis symptoms improved in pooled trials. That finding rests on only two studies and about 272 people, though, so the picture is still fairly narrow.
- Best evidence:
Fish Oil
Fish oil comes from fatty fish and supplies the omega-3 fats EPA and DHA, which help build cell membranes and regulate inflammation. People mostly look at it for heart health, but across more than 140,000 people with cardiovascular disease, studies found no clear difference in deaths from any cause. Atrial fibrillation results after bypass surgery were mixed, from just one trial of about 400 people, so the evidence is limited.
- Best evidence:
Creatine
Creatine is a compound your body makes and gets from meat and fish, and muscles store it as phosphocreatine to regenerate ATP, the fuel for quick, powerful efforts. Most people look at it for general athletic performance, where the evidence is strong, and trials found jump height went up and anaerobic capacity improved, though the gains were small. Research on endurance-style exercise was very limited and found no clear difference.
- Best evidence:
Saffron
Saffron is a spice from the Crocus sativus flower, and its compounds crocin and safranal appear to influence brain chemicals such as serotonin and dopamine. People mostly look at it for depression, where the evidence is strong, and reviews of randomized trials found that anxiety symptoms improved too. Still, the effects were small, and in one small group of 74 people appetite showed no clear difference.
- Best evidence:
Ashwagandha
Ashwagandha is a root herb from Ayurvedic tradition, classed as an adaptogen because it appears to steer the body's stress-hormone system and lower cortisol. People mostly look at it for stress, where the evidence is strong, and across five studies with about 540 people, anxiety symptoms improved. The anxiety findings are moderate in strength, though, and results for other uses, like blood sugar, rest on small, limited studies.
- Best evidence:
Resveratrol
Resveratrol is a plant compound found in grape skins and berries that works as an antioxidant and calms inflammation. People mostly look at it for kidney health, and the evidence is moderate: blood urea nitrogen, a waste marker the kidneys clear, went down, and inflammatory bowel disease symptoms improved in one trial. Those studies were small, though, and the bowel result rests on just 105 people.
- Best evidence:
Vitamin D
Vitamin D is a vitamin your skin makes in sunlight, which the body uses like a hormone to absorb calcium and support bones and immune defenses. People mostly look at it to keep their levels adequate, since shortfalls are common worldwide, and the evidence is strong for that role; trials also found fewer falls and better bone density. The bone density findings rest on small studies, so the evidence there is only moderate.
- Best evidence:
Spirulina
Spirulina is a blue-green alga eaten as a dried powder or tablet, rich in protein and in a pigment called phycocyanin that may influence immune signaling. Most people look at it for seasonal allergies, and trials found allergy symptoms improved, with moderate evidence behind that result. Only two studies, with 194 people in total, contributed to it, so the picture is encouraging but still fairly narrow.
- Best evidence:
Chromium
Chromium is a trace mineral that helps insulin do its job, supporting how cells pick up sugar from the blood. People mostly look at it for blood sugar balance, and in metabolic syndrome, six small studies found blood glucose improved, though the evidence is limited. In type 2 diabetes, trials found no clear difference in antioxidant enzymes or adiponectin, and the evidence there is very limited.
- Best evidence:
Vitamin E
Vitamin E is a fat-soluble vitamin that acts as an antioxidant, protecting cell membranes from oxidative damage. People most often look at it for nonalcoholic fatty liver disease, where the evidence is strong and a large trial in NASH found improved liver tissue features. Still, the few studies on death from any cause or bilirubin found no clear difference, and that evidence is very limited.
- Best evidence:
Cocoa Extract
Cocoa extract is a concentrated source of cacao flavanols, plant compounds that help blood vessel walls make nitric oxide so the vessels relax and widen. Most people look at it for high blood pressure, where the evidence is strong and a Cochrane review found pressure came down. Beyond that the evidence is thinner, and one small study of 20 people found no clear difference in adiponectin.
- Best evidence:
Coenzyme Q10
Coenzyme Q10 is a compound your cells use in their mitochondria to make energy, and it also acts as an antioxidant. People mostly look at it for heart health, and small trials in coronary artery disease found antioxidant enzyme activity went up, though the evidence is limited. Trials in heart failure and after a heart attack found no clear difference in exercise tolerance or HDL cholesterol, and they were very small.
- Best evidence:
Vitamin C
Vitamin C is an essential vitamin and antioxidant that the body uses to build collagen and keep immune cells working. People most often look at it for the common cold, but the evidence there is very limited: one large trial of about 1,700 people found no clear difference in cold symptoms. That rests on a single study, and the more encouraging findings, like blood flow going up, come from small trials.
- Best evidence:
Magnesium
Magnesium is a mineral that helps hundreds of enzymes run, keeping nerves, muscles and the heart working normally. People look at it most often for migraine, where the evidence is strong and research pointed to fewer, milder attacks. Beyond that, trials found no clear difference for muscle cramps, though blood pressure improved, with moderate evidence.
- Best evidence:
Panax Ginseng (Korean Ginseng)
Panax ginseng is a root used for centuries in Asian herbal medicine, and its ginsenosides are thought to boost nitric oxide, which relaxes smooth muscle and widens blood vessels. People most often look at it for erectile dysfunction, and small trials found erections went up, with the evidence rated moderate. Those studies were small, involving under 200 people in total, so larger trials would give a firmer picture.
- Best evidence:
Probiotics
Probiotics are live bacteria and yeasts that join the microbes in your gut, helping with digestion, the intestinal lining, and immune signaling. People most often look at them for H. pylori infection, where the evidence is strong and abdominal pain improved, and trials also found diarrhea symptoms eased in acute gastroenteritis. That diarrhea evidence is moderate, drawn from four studies of about 1,100 people, some of them children or people on chemotherapy.
- Best evidence:
Astaxanthin
Astaxanthin is a red carotenoid antioxidant, found in algae and salmon, that builds up in the skin and helps shield cells from oxidative damage. People mostly look at it for skin health and aging, and the evidence is moderate, with a randomized trial reporting improved skin condition. Still, one skin-related measure, bilirubin, showed no clear difference in 65 people, and research on digestive symptoms is limited and mixed.
- Best evidence:
DHEA
DHEA is a hormone made by the adrenal glands that the body uses as a raw material for sex hormones such as testosterone and estrogen. People mostly look at it for low sexual desire and sexual dysfunction in women, but the evidence is very limited, and the one small trial of 79 women found no clear difference in libido. Research is thin and the studies were small, so it is hard to say who, if anyone, benefits.
- Best evidence:
Whey Protein
Whey protein is a milk protein rich in essential amino acids, especially leucine, which the body uses to build and repair muscle. People mostly look at it for muscle size and strength, where the evidence is strong, and in older women body fat also went down. Those body-fat results came from small studies and the evidence is limited, and hospital stay after surgery showed no clear difference.
- Best evidence:
Cannabis
Cannabis is a plant whose compounds, including THC and CBD, act on the body's endocannabinoid system, which helps regulate pain, appetite and muscle tone. Most people look at it for multiple sclerosis symptoms like spasticity, pain and bladder trouble, where the evidence is moderate, though thinking skills showed mixed results. Beyond MS the evidence is limited, and small trials in cancer-related pain found pain improved.
- Best evidence:
Conjugated Linoleic Acid
Conjugated linoleic acid, or CLA, is a family of fatty acids in meat and dairy that appear to influence how fat cells store and release fat. People mostly look at it for weight management, but trials found no clear difference in body fat or in adiponectin, a hormone from fat tissue. The evidence is very limited, and the studies were small, with only 76 people across seven body fat studies.
- Best evidence:
L-Tyrosine
L-tyrosine is an amino acid your body uses to build dopamine, norepinephrine and adrenaline, chemical messengers that shape alertness and the stress response. People mostly look at it for exercise in hot weather, but the evidence is very limited: studies found no clear difference in aerobic performance, and alertness was much the same in a warm-environment soccer test. Those studies were small, under 35 people, so a benefit can't be ruled out.
- Best evidence:
Ginkgo Biloba
Ginkgo biloba is a leaf extract from an ancient tree, thought to improve blood flow to the brain and give neurons antioxidant protection. People mostly look at it for dementia, but a large trial of over 6,000 older adults found no clear difference in Alzheimer's disease risk. A small pilot study of 80 people with vascular cognitive impairment did find brain blood flow went up, so the evidence is limited.
- Best evidence:
Colostrum
Colostrum is the antibody-rich first milk produced after birth, usually from cows in supplements, packed with immune proteins and growth factors that help protect a newborn's gut. People often look at it for digestive problems, and in short bowel syndrome, muscle mass improved in a small trial, though the evidence is limited. That study included only eight people, and research in cyclists found no clear difference in aerobic performance.
- Best evidence:
Citrulline
Citrulline is an amino acid the body converts into arginine, which it uses to make nitric oxide, a molecule that relaxes blood vessels. People most often look at it for erectile dysfunction, where the evidence is moderate, including a randomized trial in men with mild cases. For athletic performance, small studies found no clear difference in aerobic or anaerobic measures, so that evidence is very limited.
- Best evidence:
Rhodiola Rosea
Rhodiola rosea is a root herb from cold, high-altitude regions, called an adaptogen because it is thought to influence how the body's stress-hormone system responds to pressure. People mostly look at it for mental resilience during stress, where the evidence is strong, and studies found anxiety symptoms eased and attention and alertness improved. Still, the studies were small, and the alertness finding rests on just 26 people.
- Best evidence:
Theanine
Theanine is an amino acid found mainly in tea that appears to raise alpha brain waves and influence calming messengers like GABA and serotonin, promoting relaxed alertness without sedation. Most people look at it for stress, and the evidence is moderate: in small trials, anxiety symptoms improved. Those findings rest on two studies with only 51 people in total, and research on alertness found no clear difference, so the picture is still preliminary.
- Best evidence:
Berberine
Berberine is a yellow plant compound found in several herbs, and it switches on AMPK, an enzyme that helps cells manage energy and blood sugar. Most people look at it for type 2 diabetes, where the evidence is strong overall, and trials found blood glucose improved in people with fatty liver and apolipoprotein B, a cholesterol-carrying protein, improved in people with diabetes. Those individual findings are only moderate, though, and the apolipoprotein B study was small.
- Best evidence:
Betaine
Betaine is a nutrient found in beets and grains that acts as a methyl donor, helping the liver process homocysteine and fat. People mostly look at it for nonalcoholic steatohepatitis, where liver enzymes improved with moderate evidence, and betaine-containing toothpaste and mouthwash also eased dry mouth symptoms and increased saliva. Still, the liver finding came from about 30 people, while blood sugar, blood flow, and athletic performance studies found no clear difference.
- Best evidence:
Zinc
Zinc is an essential mineral that helps immune cells develop and work properly, and it also supports cell division and tissue repair. Most people look at it for immune health, and the evidence for acute respiratory infections is strong: a large review found people had fewer infections, and cold symptoms eased in a smaller body of research. Much of the cold data came from small studies, and one small trial in older adults found no clear difference in upper respiratory infections.
- Best evidence:
Melatonin
Melatonin is a hormone your brain releases in the evening that tells your body it is time to sleep and helps set your internal clock. Most people look at it for sleep and insomnia, and the evidence is strong: in five studies, insomnia symptoms improved, including in older adults and in children who struggled to fall asleep. Those studies were fairly small, though, with 259 people in total, so the findings say more about who was studied than about everyone.
- Best evidence:
HMB
HMB is a natural byproduct of leucine, an amino acid, and it appears to slow the breakdown of muscle protein in the body. People mostly look at it for muscle size and strength, and the evidence is moderate, though anaerobic capacity in 28 people and body fat in people with sarcopenia showed no clear difference. Those results are very limited, so they say little about muscle gain itself.
- Best evidence:
Sodium Bicarbonate
Sodium bicarbonate is baking soda, an alkaline salt that works as one of the blood's main buffers, soaking up excess acid to keep the body's chemistry steady. Athletes mostly look at it for rowing and other high-intensity efforts, where the evidence is strong and studies found anaerobic capacity improved. Still, the studies behind those findings were small, and in cyclists adrenaline showed no clear difference.
- Best evidence:
Caffeine
Caffeine is a stimulant in coffee and tea that blocks adenosine, a brain chemical that builds up and makes you feel tired. People mostly look at it for athletic performance, and the evidence is strong for aerobic exercise, where trials found endurance measures improved, with agility improving too. The agility findings came from small studies, and evidence for sprint-type efforts was limited.
- Best evidence:
Niacin (Vitamin B3)
Niacin is vitamin B3, a nutrient your cells use to make molecules that carry energy. People mostly look at it for high cholesterol, where the evidence is moderate, and in one trial of people with low HDL on statins, apolipoprotein A, HDL's main protein, went up. Large studies found no clear difference in deaths overall or from heart disease, though, so heart benefits remain unproven.
- Best evidence:
Tongkat Ali
Tongkat ali is a Southeast Asian shrub whose root extract has long been used in traditional medicine and is thought to influence male hormones, including testosterone. People mostly look at it for sexual health and vitality, and the evidence is moderate: a meta-analysis of randomized trials found erections went up. That finding came from a single small group of 128 people, so it is too early to say how well it holds up in larger or longer studies.
- Best evidence:
Black seed
Black seed is the seed of Nigella sativa, a flowering plant, and it contains thymoquinone, a compound studied for its antioxidant and anti-inflammatory activity. People most often look at it for hay fever, where the evidence is strongest: a trial of 257 people found allergy symptoms improved. That rests on a single study, though, and other findings, such as blood sugar and blood pressure improvements, come with only moderate evidence.
- Best evidence:
Green Tea Extract
Green tea extract is a concentrated source of catechins, plant antioxidants that slow the breakdown of norepinephrine, a body signal that helps drive fat burning. People mostly look at it for weight management, where the evidence is moderate overall, though two trials found no clear difference in body fat, and blood pressure improved in small studies of people with obesity. Most studies were small, so the evidence for any single result is limited.
- Best evidence:
Inositol
Inositol is a sugar-like compound the body makes that helps cells respond to insulin and relay signals. Most people look at it for polycystic ovary syndrome (PCOS), where the evidence is strong overall, and trials found blood glucose improved and acne symptoms eased. Still, the glucose result came from two small studies and the acne result from one trial of 50 women.
- Best evidence:
Red Clover Extract
Red clover extract comes from a clover plant rich in isoflavones, compounds the body converts into genistein and daidzein, which support estrogen balance. People mostly look at it for menopause symptoms, and the evidence is moderate: in one study of 189 women, anxiety symptoms eased. That finding rests on a single study, though, and a menopause trial of 53 people found no clear difference in apolipoprotein A, so the picture is thin.
- Best evidence:
Tribulus Terrestris
Tribulus terrestris is a plant used in traditional medicine, and its extracts may nudge sex hormones such as testosterone and luteinizing hormone. Most people look at it for sexual function, and in women with sexual dysfunction, studies found libido went up, with moderate evidence; results for erections in men were more limited. The studies were small, and the few that measured luteinizing hormone or free testosterone found no clear difference.
- Best evidence:
Hesperidin
Hesperidin is a flavonoid found in citrus fruit, especially oranges, that works as an antioxidant and may influence how blood vessels behave. In a small trial, apolipoprotein B, a cholesterol-carrying protein, improved, with moderate evidence, and blood flow went up in a study of nine people. Blood glucose showed no clear difference, and most findings come from small studies.
- Best evidence:
Tetradecyl Thioacetic Acid
Tetradecyl thioacetic acid is a modified fatty acid with a sulfur atom in its chain, which the body cannot burn for fuel like ordinary fats and which switches on fat-handling genes instead. In people with high cholesterol, small studies found apolipoprotein B improved and cell adhesion factors went down, though the evidence is limited. Those trials enrolled only 10 to 43 people, and blood glucose showed no clear difference in 18 people.
- Best evidence:
Lactobacillus reuteri
Lactobacillus reuteri is a probiotic bacterium that lives naturally in the gut, where it helps shape the microbe community. People mainly look at it for acute diarrhea from gastroenteritis, where the evidence is strong, and trials also found babies with colic cried less and H. pylori outcomes improved. The colic and H. pylori findings came from small or moderate studies and the evidence is moderate, while blood sugar and cholesterol showed no clear difference.
- Best evidence:
Maca
Maca is a root vegetable from the high Peruvian Andes, long eaten as food and used traditionally as an adaptogen, meaning a plant thought to help the body handle stress. People mostly look at it for sexual desire and function, and the evidence is limited: a small trial found libido went up. That pilot study followed only 20 sportsmen, so it says little about women, older adults, or long-term use.
- Best evidence:
Rose Hip
Rose hip is the vitamin C-rich fruit left after a rose blooms, and it holds plant compounds that act as antioxidants. The evidence is limited, but skin dryness improved in a small trial of 34 people, and chemotaxis, the movement of immune cells toward inflammation, went down in a study of just eight. C-reactive protein and blood glucose showed no clear difference, and the studies were small.
- Best evidence:
Flaxseed
Flaxseed is a fiber-rich seed that contains plant compounds called lignans, which have weak estrogen-like activity in the body. People mostly look at it for menopausal hot flashes, though the evidence for that use is limited. Its better-supported results came from type 2 diabetes, where moderate evidence from trial reviews found blood glucose improved, although the effect was small.
- Best evidence:
Beta-Alanine
Beta-alanine is an amino acid the body uses to build carnosine, a compound in muscle that helps buffer the acid that builds up during hard effort. People mostly look at it for climbing and other high-intensity sport, where the evidence is strong, and in cyclists anaerobic capacity improved. That cycling finding came from just two small studies, though, and research found no clear difference in body fat or aerobic fitness.
- Best evidence:
Arginine
Arginine is an amino acid the body uses to build proteins and to make nitric oxide, a molecule that relaxes blood vessels and helps blood flow. People mostly look at it for intermittent claudication, the leg pain that comes on with walking, and one small trial of 39 people found blood flow went up, though the evidence is limited. Results for related symptoms were mixed, so this is early, small-scale work that can't say much yet.
- Best evidence:
Boron
Boron is a trace mineral found in plants and water that helps the body handle calcium and vitamin D, which bones and joints rely on. People mostly look at it for rheumatoid arthritis, and the evidence is limited: three small trials found levels of C-reactive protein, a marker of inflammation, went down. Those studies included only about 80 people, and some tested boron alongside a standard arthritis drug, so the findings are early.
- Best evidence:
D-Ribose
D-ribose is a sugar your cells use to rebuild ATP, the molecule that powers muscles and the heart. People mostly look at it for heart failure and cardiomyopathy, where the evidence is moderate, and in one small group with heart failure, angina improved. Still, the studies were small, and in exercise trials ribose showed no clear difference in aerobic performance.
- Best evidence:
Vitamin K
Vitamin K is a fat-soluble vitamin that helps the body activate proteins needed for blood clotting and for binding calcium into bone. People mainly look at it for newborn nutritional support, where the evidence is strong, and for bone health, where reviews of trials found bone density improved. The size of that benefit was moderate, though, and inflammation markers, blood pressure and bruising showed no clear difference in small studies.
- Best evidence:
Chia seeds
Chia seeds are the tiny seeds of Salvia hispanica, a mint-family plant, and they supply fiber, plant omega-3 fats and protein. Evidence is limited, but appetite went down in one small study of 11 people, and chia seed oil on the skin eased itching in five. A review covering 362 people found no clear difference in blood glucose, though that evidence is very limited.
- Best evidence:
Phosphatidylserine
Phosphatidylserine is a fat-like phospholipid that sits in the membranes of brain cells, where it helps nerve cells signal to one another. People mostly look at it for memory problems such as mild cognitive impairment, and small trials found cognition and forgetting improved, though the evidence is limited. Those studies were tiny, with 8 to 18 people each, and one tested it alongside omega-3 fats, so the findings are early.
- Best evidence:
N-Acetylcysteine
N-acetylcysteine is a modified form of the amino acid cysteine that the body uses to build glutathione, a key antioxidant, and it also thins mucus. People mostly look at it for chronic obstructive pulmonary disease (COPD), and a meta-analysis of oral use found bronchitis symptoms improved, though the evidence there is moderate. Another COPD outcome, chronic bronchitis, showed no clear difference, and the studies behind these findings were small.
- Best evidence:
Fenugreek
Fenugreek is a seed from a clover-like plant, used for centuries in cooking and traditional medicine, that contains fibre and plant compounds called saponins thought to act on hormones and digestion. Most people look at it for breast milk production, and the evidence is moderate: in two small studies of 164 mothers, milk production went up. Those trials mostly tested herbal teas that combined several ingredients, so it is hard to credit fenugreek alone.
- Best evidence:
Iron
Iron is a mineral the body uses to build hemoglobin, the protein in red blood cells that carries oxygen. People mostly look at it during pregnancy for healthy birth weight, where the evidence is moderate: a meta-analysis in women with normal iron status found birth weight changed, though the direction wasn't clear. That result rested on a single small study of 361 women, and it applies only to women whose iron was already normal.
- Best evidence:
Coleus forskohlii
Coleus forskohlii is a mint-family plant whose root contains forskolin, a compound thought to raise cAMP, a signal that helps cells regulate fat metabolism. People mostly look at it for bone health, where the evidence is limited, and the related trials found body fat went down while appetite showed no clear difference. Those studies were small, with around 30 people, so it is too early to say much more.
- Best evidence:
Psyllium
Psyllium is a soluble fiber from Plantago ovata seed husks that forms a gel in the gut, helping regulate bowel movements. People mostly look at it for digestive health, and trials found it changed stool weight, while constipation symptoms eased in a larger review. The stool studies were small, though, and the constipation evidence is limited.
- Best evidence:
Ginger (Zingiber officinale)
Ginger is a pungent root whose compounds act on the gut, likely by blocking serotonin signals that spark nausea. People look at it most for nausea and vomiting in pregnancy, and the evidence is strong: pooled trials found nausea improved compared with placebo, and severe vomiting symptoms were less likely. The improvements were moderate in size, and results for nausea after surgery or chemotherapy were more mixed.
- Best evidence:
Nitrate
Nitrate is a compound found in beetroot and leafy greens that the body converts into nitric oxide, a molecule that helps blood vessels relax and muscles use oxygen efficiently. People mostly look at it for endurance exercise, where the evidence is strong, and studies found aerobic exercise measures improved. Blood lactate during exercise showed no clear difference, though, and the aerobic finding itself came from a small group of about 20 people.
- Best evidence:
Velvet Antler
Velvet antler is the soft, skin-covered tissue of a growing deer or elk antler, which supplies the proteins and minerals behind its fast growth. People mostly look at it for rowing performance, but the evidence is very limited, and a study of 46 people found no clear difference in anaerobic capacity. Other small trials on aerobic fitness and rheumatoid arthritis symptoms also found no clear difference.
- Best evidence:
Alpha-Linolenic Acid (ALA)
Alpha-linolenic acid (ALA) is a plant-based omega-3 fat found in foods like flaxseed and walnuts, which the body uses for energy and can convert in small amounts into other omega-3s. People mostly look at it for blood pressure in those with obesity, and studies there found mixed results, though the evidence is moderate. Beyond that, research found no clear difference for blood sugar in type 2 diabetes, HDL cholesterol, or death from any cause, and that evidence is very limited.
- Best evidence:
Omega-3 Fatty Acids
Omega-3 fatty acids, such as EPA and DHA, are fats that build cell membranes, including in the brain, and help steer inflammation. People most often look at them for major depression, where the evidence is limited: anxiety symptoms eased in people with depression, and pooled studies found depression symptoms improved. Those trials were small, including one analysis of just 50 people, so these are early findings.
- Best evidence:
Docosahexaenoic Acid
DHA is an omega-3 fat from fish and algae that helps build cell membranes in the brain and eyes. In a small study of 22 people, blood flow to the brain went up, though the evidence is limited, and a large pregnancy trial found no clear difference in postpartum depression symptoms. Results for sleep, child behavior and immune cells also showed no clear difference, on very limited evidence.
- Best evidence:
Lavender
Lavender is a fragrant herb whose oil contains linalool and linalyl acetate, compounds that appear to calm nerve activity by acting on GABA-A receptors and calcium channels. People mostly look at it for stress, and across four studies with 1,893 participants, anxiety symptoms improved, with moderate evidence. Some studies took place in dental offices using lavender scent, and heart rate and blood pressure findings came from small studies.
- Best evidence:
Branched-Chain Amino Acids
Branched-chain amino acids are leucine, isoleucine, and valine, three essential amino acids from protein foods that muscles use as building blocks and fuel. People mostly look at them for muscle recovery, where the evidence is moderate, but a single study of 12 people measuring ammonia after exercise found mixed results. Other studies were also small, and several found no clear difference in things like blood glucose or stress hormones.
- Best evidence:
Lemon Balm
Lemon balm is a lemon-scented herb in the mint family whose extracts are thought to raise levels of GABA, a calming chemical messenger in the brain. Most people look at it for stress, and trials found that anxiety symptoms improved, with moderate evidence behind that result. Those studies were fairly few, though, and some tested lemon balm blended with other calming herbs, so its own effect is harder to pin down.
- Best evidence:
Tart Cherry Juice
Tart cherry juice is a juice from sour cherries that is rich in anthocyanins, plant pigments with anti-inflammatory effects in the body. Most people look at it for gout, but the evidence is very limited: a small trial of 50 people found no clear difference in gout symptoms or in HbA1c. Those results come from a single small study, so they cannot say much either way, and the same kind of no-clear-difference finding appeared in tiny studies on blood glucose and aerobic exercise.
- Best evidence:
Bacopa Monnieri
Bacopa monnieri is an Ayurvedic herb whose active compounds, called bacosides, are thought to support communication between nerve cells and protect them from damage. Most people look at it for memory, and the evidence is moderate: trials in about 645 people found memory scores improved, though the effect was small. Attention showed no clear difference, and a small study in Alzheimer's disease found none either, so the findings mostly apply to memory in generally healthy adults, including older ones.
- Best evidence:
Ephedrine
Ephedrine is a stimulant compound from the ephedra plant that activates adrenaline-related receptors, which speeds the heart and raises how much energy the body burns. Studies found metabolic rate went up, and the evidence for that is moderate, though the five studies involved only 17 people in total. Evidence for lower body fat and appetite was limited, and limited research also found blood pressure got worse.
- Best evidence:
Licorice
Licorice is a root whose glycyrrhizin makes the body hold on to more sodium, which nudges blood pressure upward. People mostly look at it for low blood pressure on standing, though the evidence is limited, with about 150 participants studied. Other small studies found LDL oxidation improved in 19 people, while cortisol changed in an unclear direction and estrogen showed no clear difference.
- Best evidence:
Reishi
Reishi is a mushroom used in traditional Asian medicine, rich in beta-glucans, compounds that interact with immune cells in the body. People mostly look at it for support during cancer care, and small trials found immune measures improved in patients, though the evidence is limited. Those studies were small, with only a few dozen participants in total, and trials on prostate symptoms and blood flow found no clear difference, so the picture is still early.
- Best evidence:
Quercetin
Quercetin is a plant pigment found in onions, apples, and tea that works as an antioxidant and may steady mast cells, the immune cells that release histamine. People mostly look at it for allergies, including hay fever, where the evidence is moderate. Beyond that, research is thin: one small study found HDL cholesterol improved, while others found no clear difference in blood pressure or sprint performance.
- Best evidence:
Taurine
Taurine is an amino acid found in high amounts in the heart, muscles and brain, where it helps regulate calcium handling and protect cells from oxidative stress. People mostly look at it for heart failure, and the evidence is limited: three small studies of 29 people found blood pressure improved. Those findings came from very small groups, and some of the supporting work looked at people with prehypertension rather than heart failure itself, so they say little about heart failure outcomes.
- Best evidence:
Chlorella
Chlorella is a single-celled freshwater green alga, rich in protein, chlorophyll, iron and B vitamins, that people eat as a nutrient-dense food supplement. Most people look at it for iron deficiency anemia, and the evidence is limited: one small trial in pregnant women found their risk of anemia improved. Because that finding comes from a single study of 70 people, it is too early to say how well it applies to others.
- Best evidence:
Resistant Starch
Resistant starch is a carbohydrate that escapes digestion and reaches the colon, where it feeds friendly gut bacteria that make butyrate. People mostly look at it for digestive wellness, and the evidence is strong: trials found fecal short-chain fatty acids rose. Support was moderate for lower blood glucose in type 2 diabetes, while very limited work on PCOS inflammation and kidney markers found no clear difference.
- Best evidence:
Glutamine
Glutamine is the most abundant amino acid in the blood, and cells lining the gut and immune cells use it as a key fuel. People mostly look at it during cancer treatment, and the evidence is moderate that it may lessen the severity of mouth and throat sores caused by radiation in head and neck cancer. Studies in other areas were small, and for Crohn's disease symptoms they found no clear difference.
- Best evidence:
Soy Protein
Soy protein is a plant protein made from soybeans that supplies amino acids for building tissue, and it also carries isoflavones, plant compounds that bind estrogen receptors in bone. People mostly look at it for osteoporosis, but the evidence there is limited, and no clear bone findings stand out yet. Research is firmer for muscle, where trials found small gains in muscle mass and strength.
- Best evidence:
Krill Oil
Krill oil is an oil from small Antarctic crustaceans that supplies the omega-3 fats EPA and DHA, which help build cell membranes and shape how the body manages inflammation. People most often look at it for rheumatoid arthritis, and a trial of 90 people found arthritis symptoms improved, though the evidence is limited. That finding comes from a single moderate-sized study, so it needs more trials to confirm it, and the other results so far, such as lower CRP in knee osteoarthritis, are similarly limited.
- Best evidence:
Folic Acid (Vitamin B9)
Folic acid is the supplement form of vitamin B9, which the body uses to make DNA and help cells divide, especially during rapid fetal growth. People mostly look at it for pregnancy, where the evidence is strong overall, though research on infant birth weight found mixed results. That finding rests on just two studies of about 700 women, and a small review in infertile men found sperm motility improved.
- Best evidence:
Medium-chain Triglycerides
Medium-chain triglycerides are fats with shorter carbon chains than most dietary fats, so the body absorbs them quickly and the liver readily turns them into energy and ketones. The evidence is moderate for cognition, which improved in trials, and limited for fat oxidation, which went up. Still, the studies were small, the fat oxidation work involved only 12 people, and blood markers such as apolipoproteins showed no clear difference.
- Best evidence:
Umckaloabo
Umckaloabo is a herbal extract made from the roots of Pelargonium sidoides, a South African geranium, traditionally used for chest and airway complaints and thought to influence how the body responds to respiratory infections. People mostly look at it for bronchitis, and the evidence is strong: pooled trials, including one in children and adolescents, found bronchitis symptoms improved. Smaller studies pointed to eased asthma symptoms during colds, but that rests on a single trial of 61 children, so it is limited.
- Best evidence:
Alpha-Lipoic Acid
Alpha-lipoic acid is an antioxidant the body makes in small amounts, helping cells produce energy and limit oxidative stress. Most people look at it for diabetic neuropathy, where the evidence is strong, though related studies found only a small improvement in fasting blood glucose and no clear difference in blood pressure. The glucose finding came from just 38 people, and one trial found no clear difference in overall blood sugar control.
- Best evidence:
Eleuthero
Eleuthero is the root of a shrubby Asian plant, often called Siberian ginseng, traditionally used as an adaptogen to help the body cope with physical strain. Research is limited, but in athletic performance a small trial found anaerobic capacity improved. That trial had just six people, and another in 31 people found no clear difference in heart rate, so the picture is far from settled.
- Best evidence:
Bitter Cucumber
Bitter cucumber is a bitter-tasting, gourd-family plant whose fruit has long been used in traditional herbal medicine rather than as a nutrient the body needs. The best-supported finding was that blood glucose improved in a small study of 50 people with high cholesterol, though the evidence is limited. Other work found no clear difference in HDL cholesterol or blood pressure, and that evidence is very limited.
- Best evidence:
Grape Seed Extract
Grape seed extract is a concentrated source of proanthocyanidins, plant compounds from grape seeds that act as antioxidants and help keep small blood vessel walls firm. People mostly look at it for vein problems such as chronic venous insufficiency, where the evidence is moderate. Beyond veins, studies found blood pressure improved and blood flow went up, though the blood flow work involved only a few dozen people.
- Best evidence:
Kava
Kava is a drink and extract made from the root of a Pacific Island plant, whose active compounds, called kavalactones, act on calming GABA receptors in the brain. People mostly look at it for anxiety, and the evidence is strong: a pooled analysis of seven studies found anxiety symptoms improved. Those studies were moderate in size, with 380 people in total, and the evidence for sleep and thinking was limited, resting on very small groups.
- Best evidence:
Nicotine
Nicotine is a stimulant best known from tobacco that switches on nicotinic receptors on nerve cells, shaping attention, alertness and mood. The evidence is limited, but in one small trial of healthy non-smoking men, reaction time improved, while a separate study in 67 people found mixed effects on anxiety. Other outcomes, including blood pressure, libido and fat burning, showed no clear difference, and the studies were few and small.
- Best evidence:
Peppermint
Peppermint is an aromatic herb whose oil contains menthol, which blocks calcium channels in the gut's smooth muscle and helps it relax. Most people look at it for irritable bowel syndrome, and the evidence is strong: across seven studies, symptoms improved. Those studies were only moderate in size, about 392 people in total, and findings for related gut outcomes like gas and colon tension rest on small, limited studies.
- Best evidence:
Nicotinamide Mononucleotide
Nicotinamide mononucleotide, or NMN, is a small molecule the body uses to make NAD+, a compound cells rely on to turn food into energy. People mostly look at it for aging muscle and metabolism, but studies found no clear difference in muscle mass, insulin resistance, or walking ability, and the evidence is very limited. Only a handful of small trials exist, so it is too early to say much either way.
- Best evidence:
Leucic Acid
Leucic acid is a compound the body produces as it breaks down leucine, an amino acid that helps muscles build protein. People mostly look at it for body composition, but the evidence is very limited: research involving 15 people found no clear difference in body fat or anaerobic capacity. With so few participants, it is too early to say whether it changes body fat or athletic performance.
- Best evidence:
Pycnogenol
Pycnogenol is a standardized extract of French maritime pine bark, rich in plant antioxidants that may help strengthen small blood vessels and calm inflammation. People mostly look at it for chronic venous insufficiency, where leg veins struggle to return blood, and a controlled trial of 126 people found their signs of the condition improved, with moderate evidence overall. That evidence rests largely on one modest trial, and the other findings, such as better blood flow and osteoarthritis symptoms, came from small or single studies.
- Best evidence:
Gamma Oryzanol
Gamma oryzanol is a group of plant compounds found in rice bran oil, where they act as antioxidants that protect the oil, and it is sold as a supplement. People mostly look at it for cholesterol, but the research is thin: one small trial of 30 men with mildly high cholesterol found no clear difference in LDL or HDL. Evidence is very limited, and a separate study of 22 people also found no clear change in the stress hormone cortisol.
- Best evidence:
Milk Protein
Milk protein is the protein portion of milk, mostly casein and whey, which supplies the amino acids the body uses to build and repair tissues. People with type 2 diabetes often look at it for blood sugar, and a review of controlled meal trials found mixed results, with moderate evidence overall. Blood pressure improved slightly in that group, while appetite showed no clear difference in a tiny weight-loss study of 17 people.
- Best evidence:
Policosanol
Policosanol is a mixture of waxy alcohols, usually extracted from sugar cane, that is thought to influence how the body makes cholesterol and clears LDL from the blood. People mostly look at it for atherosclerosis, the artery-narrowing plaque buildup, and the evidence is limited: small trials found HDL, the "good" cholesterol, went up. Those studies were small, and one trial of 66 people found no clear difference in blood flow.
- Best evidence:
Safflower Oil
Safflower oil is a vegetable oil pressed from safflower seeds, and it supplies unsaturated fats such as linoleic acid that the body uses to build cell membranes and store energy. People with type 2 diabetes look at it for blood sugar, but the evidence is very limited, and research found no clear difference in blood glucose or body fat. Only 35 participants were involved, so this work can't say much either way.
- Best evidence:
Synbiotics
Synbiotics pair live beneficial bacteria with prebiotic fibers that feed them, aiming to support the community of microbes in your gut. The best-supported research looked at blood pressure in people with fatty liver disease, where the evidence is moderate but results were mixed across 319 participants. Elsewhere, studies found no clear difference in abdominal pain in irritable bowel syndrome, body fat in fatty liver disease, or height in malnutrition, and that evidence is very limited.
- Best evidence:
Calcium
Calcium is a mineral that builds and maintains your bones and teeth and helps nerves and muscles work. Its main use in the research here is bone health, though the clearest trial findings came from pregnancy, where calcium was linked to a lower risk of preeclampsia and the evidence is strong. Those results came from a handful of trials and reviews, and the effect size was moderate. The benefit was seen mostly in women with low dietary calcium.
- Best evidence:
Green Coffee Extract
Green coffee extract comes from unroasted coffee beans and is rich in chlorogenic acids, plant compounds that may influence how the body handles sugar and fat. The evidence is moderate for blood glucose, which improved in research involving 405 people, and a small trial also found better homocysteine levels. Even so, most studies were small, evidence for blood pressure and body fat is limited, and body mass index showed no clear difference in 1,721 people.
- Best evidence:
D-Aspartic Acid
D-aspartic acid is an amino acid that may prompt the release of luteinizing hormone, a signal that tells the testes to make testosterone. People mostly look at it for low testosterone, but the evidence there is limited, drawing on about 250 participants in total. Research in 20 people also found no clear difference in body fat or estrogen, so the research is thin overall.
- Best evidence:
Echinacea
Echinacea is a group of purple coneflower plants whose extracts are thought to nudge the immune system, helping immune cells respond to viruses. People mostly look at it for colds, and the evidence is limited: pooled trials found cold symptoms improved, and one small study found a type of immune cell went up. Those studies were small, and a measure of another immune cell showed no clear difference, so the picture is far from settled.
- Best evidence:
Pyruvate
Pyruvate is a small molecule your cells produce when they break down sugar, and it feeds into the chemistry that makes energy. People have looked at it for blood pressure in those with high cholesterol, where a small study of 40 people found improvement, though the evidence is limited. Single small studies on body fat and aerobic performance found no clear difference, so the evidence there is very limited.
- Best evidence:
S-adenosylmethionine
S-adenosylmethionine, or SAMe, is a compound your cells make from the amino acid methionine, and it donates methyl groups that help build brain chemicals and maintain cell membranes. People mostly look at it for depression, and the evidence is moderate: a pooled analysis of six studies with about 1,558 people found depression symptoms improved, though the effect was small. Much of that research tested SAMe alongside antidepressants, and one small trial of 46 people found no clear difference in attention, so the findings say little about it on its own.
- Best evidence:
Selenium
Selenium is a trace mineral the body uses for antioxidant enzymes and for converting thyroid hormone to its active form. People mostly look at it for Kashin-Beck disease, a bone and joint disorder where low selenium is a major contributing factor, and the evidence for that use is strong. For Hashimoto's thyroiditis, however, studies of 1,377 people found no clear difference in signs, and that evidence is very limited.
- Best evidence:
Wild Yam
Wild yam is a climbing vine whose root contains diosgenin, a plant compound with a structure similar to steroid hormones. The best-supported finding is for thinking skills: in a small crossover trial of 28 healthy adults, a diosgenin-rich extract improved cognition, though the evidence is limited. Other studies were also small, with blood pressure improving in one and hormone results in menopause coming out mixed.
- Best evidence:
African Mango
African mango is a West African tree whose seeds are made into an extract, and it is thought to influence fat storage and blood sugar through hormones such as adiponectin, which helps the body respond to insulin. In people with obesity, trials found adiponectin went up in one study of 102 people, and blood glucose improved in another of 40 people. Both studies were small and the evidence is limited, so these results are early and firm conclusions would be premature.
- Best evidence:
Casein
Casein is the main protein in milk, digested slowly so it releases amino acids into the blood over several hours, and it also supplies building blocks for muscle and other tissues. People most often look at it for blood pressure in those with high readings, and the evidence is moderate: blood pressure improved, meaning it went down. Those results came from small studies of 183 people, and blood glucose showed no clear difference, with very limited evidence.
- Best evidence:
Gotu Kola
Gotu kola is a creeping herb long used in Ayurvedic medicine, whose triterpene compounds help support connective tissue and small blood vessels. People look at it mostly for chronic venous insufficiency, and the evidence is strong: trials found the signs of poor leg circulation improved, and blood flow went up in a smaller group. Most of those studies were of moderate size, while the anxiety findings rest on one small trial.
- Best evidence:
Roselle
Roselle is a tart, deep-red hibiscus plant whose dried flower calyces are brewed into tea and extracts, and it contains plant pigments called anthocyanins that act as antioxidants in the body. People look at it mostly for blood pressure, and the evidence is strong: across five trials, blood pressure improved, including in adults with mildly high readings and in people with type 2 diabetes. Findings for inflammation, blood sugar and cholesterol were much thinner, with one tiny study of eight people and no clear differences for blood sugar or cholesterol.
- Best evidence:
Inulin
Inulin is a soluble fiber found in foods like chicory root and onions, which passes undigested to the gut, where bacteria ferment it and use it as fuel. People mostly look at it for prediabetes, and the evidence is moderate: reviews of trials found blood glucose improved, meaning it came down. Those findings rest on a small number of studies with about 500 participants, and trials found no clear difference in BMI, HDL cholesterol, or appetite.
- Best evidence:
Kanna
Kanna is a succulent plant from southern Africa, traditionally chewed or brewed for its mood-lifting effects, and it contains alkaloids thought to act on the brain's serotonin system. People mostly look at it for dementia, and the evidence is limited: a small trial found cognition improved. Only a few small studies exist, with a handful of participants each, and one stress test found no clear difference in reaction time, so firm conclusions aren't possible yet.
- Best evidence:
Olive Leaf Extract
Olive leaf extract is a concentrate made from olive tree leaves, rich in plant compounds such as oleuropein that act as antioxidants in the body. The best-supported finding is for blood pressure, where studies found readings came down in people with high or borderline-high levels, and the evidence is moderate. That rests on just two studies with 188 people, and blood sugar results came from small studies with limited evidence.
- Best evidence:
Roselle
Roselle is a tart, deep-red hibiscus flower, usually steeped as tea, that is rich in anthocyanins, plant pigments thought to relax blood vessels and nudge the body to pass more water. Most people look at it for high blood pressure, and the evidence is strong: trials found blood pressure improved. Studies on inflammation, blood sugar and cholesterol were much smaller, and they found no clear difference for glucose or apolipoprotein A.
- Best evidence:
Royal Jelly
Royal jelly is a protein- and fat-rich substance that worker bees produce to feed queen bee larvae. People mostly look at it for metabolic health, and blood glucose improved in a small group of 71 people, though the evidence is limited. Blood pressure and a marker of inflammation called CRP showed no clear difference, and the evidence there is very limited, so the research is still thin.
- Best evidence:
Cinnamon
Cinnamon is a warm spice from tree bark that has long been used in food, and its compounds are thought to nudge cells to respond better to insulin, the hormone that moves sugar out of the blood. People mostly look at it for type 2 diabetes, and reviews of trials found blood glucose improved, with moderate evidence behind that result. The studies were small, though, so the picture is far from settled, and cinnamon showed no clear difference in a marker of inflammation.
- Best evidence:
Dill
Dill is a feathery herb, used in cooking, whose leaves and seeds hold aromatic oils and plant compounds. In people with high cholesterol, blood sugar control improved in a small group of about 100 people, though the evidence is limited. Another look at blood glucose in about 200 people found no clear difference, and that evidence is very limited.
- Best evidence:
Gymnema Sylvestre
Gymnema sylvestre is a woody vine from India whose leaves contain gymnemic acids, compounds that temporarily dull the taste of sweetness. The best-studied use is blood pressure, where the evidence is moderate and readings improved in people with high blood pressure. Blood glucose also improved, though that evidence is limited, and the studies were small, involving 113 people in total.
- Best evidence:
Pterostilbene
Pterostilbene is a plant compound found in blueberries, closely related to resveratrol, that acts as an antioxidant in the body. People mostly look at it for heart health, and in a small study of 80 people with coronary artery disease, blood pressure improved, though the evidence is limited. In 215 people, blood glucose showed no clear difference, and that evidence is very limited too.
- Best evidence:
D-Serine
D-serine is an amino acid made in the brain that helps switch on NMDA receptors, which nerve cells use to communicate, learn and form memories. People mostly look at it for schizophrenia, and studies of it added to usual medication found that overall symptoms and thinking skills improved, with moderate evidence for cognition and limited evidence for symptoms. The studies were small, involving a few hundred people at most, so the picture is still preliminary.
- Best evidence:
Ecdysteroids
Ecdysteroids are steroid-like compounds made by plants, chemically related to the hormones insects use to molt, though their role in the human body is still unclear. Some people look at them for body composition, and research found no clear difference in muscle mass or cortisol among 45 participants. The evidence is very limited, so this is a small early look rather than a firm answer either way.
- Best evidence:
Ursolic Acid
Ursolic acid is a waxy plant compound found in apple peels and herbs like rosemary, and it appears to influence signaling in muscle and fat tissue. The evidence is limited, but in one small study of 16 men, levels of IGF-1, a hormone tied to muscle growth, went up. Body fat and blood glucose showed no clear difference in that same small group, so it is far too early to say much more.
- Best evidence:
Yohimbine
Yohimbine is a compound from the bark of an African tree that blocks alpha-2 adrenergic receptors, which loosens a brake on the body's stress-related noradrenaline signaling. People mostly look at it for claustrophobia, where two small trials found phobia symptoms improved when it was added to exposure therapy, though the evidence is limited. Those studies were small, with only 24 participants in total, and other research noted increased anxiety in some people.
- Best evidence:
Alcohol
Alcohol is ethanol, a compound made by fermenting sugars that slows signaling between nerve cells and so dampens activity in the brain. Research has mostly looked at its effects on hormones, and the evidence is limited: testosterone results were mixed across five studies, while follicle-stimulating hormone went up in a small group of people. Estrogen, cortisol, and adrenaline showed no clear difference, and these studies were tiny, often with fewer than 30 people.
- Best evidence:
Brown Seaweed Extract
Brown seaweed extract is a concentrate of compounds from brown algae, such as fucoidan and phlorotannins, which are thought to influence digestion and inflammation. In people with fatty liver disease, small studies found blood pressure improved and C-reactive protein, a marker of inflammation, went down, though the evidence is limited. Studies on appetite in obesity and on blood glucose found no clear difference, and that evidence is very limited.
- Best evidence:
Calendula Officinalis
Calendula officinalis is the pot marigold, a flowering herb whose petals contain plant compounds with anti-inflammatory properties, and it is usually applied to the skin as a cream or ointment. People mostly look at it for skin reactions during radiation therapy, and the evidence is limited: trials found less dermatitis in some cases, though itching results were mixed. One large trial found no difference from a plain aqueous cream, so the findings are far from settled.
- Best evidence:
Fiber
Fiber is the part of plant foods your body can't digest, and it adds bulk to stool, softens it and slows how quickly carbohydrates are absorbed. People most often look at it for constipation-predominant irritable bowel syndrome, where the evidence is strong, especially for soluble fiber. Findings elsewhere were more modest: blood glucose improved in pregnancies with diabetes, though the studies were small, and appetite showed no clear difference.
- Best evidence:
Black Cohosh
Black cohosh is a North American herb whose root may act on serotonin receptors and have weak estrogen-like effects. People mostly look at it for menopause symptoms, where the evidence is rated strong, though single trials found no clear difference in anxiety or in the inflammation marker CRP. Those studies were small, and a review in women with breast cancer found symptoms eased, but that evidence is limited.
- Best evidence:
Perilla
Perilla is a leafy plant in the mint family whose seeds yield an oil rich in alpha-linolenic acid, a plant omega-3 fat the body uses for cell membranes. In people with high cholesterol, one trial found that C-reactive protein, a marker of inflammation, went down and HDL, the so-called good cholesterol, improved. That trial included only 36 people, so the evidence is limited.
- Best evidence:
7-Keto DHEA
7-Keto DHEA is a compound the body makes as a byproduct of the hormone DHEA, though unlike DHEA it does not convert into sex hormones. People mostly look at it for weight management in obesity, and the evidence is very limited: small studies hinted at a slight rise in resting metabolic rate and some fat loss. Both findings came from manufacturer-funded or conflict-of-interest research in a few dozen people, and blood sugar and blood pressure showed no clear difference.
- Best evidence:
Choline
Choline is an essential nutrient the body uses to build cell membranes and make acetylcholine, a chemical messenger involved in memory and muscle control. People mostly look at it for child development, since it supports brain growth, and the evidence for that is moderate, from about 1,000 participants. Small studies in athletes, with 20 and 13 people, found no clear difference in anaerobic capacity or cognition, so that evidence is very limited.
- Best evidence:
Alanylglutamine
Alanylglutamine is a compound of two amino acids, alanine and glutamine, that the body splits to supply glutamine, a fuel for immune and gut cells. People mostly look at it for exercise fatigue, and fatigue symptoms improved in a small group of 10 basketball players, though the evidence is limited. Other small studies found no clear difference in heart rate, a stress hormone in cyclists, or immune cells in people with HIV.
- Best evidence:
Beta-glucans
Beta-glucans are soluble fibers found in oats, barley and yeast, and in the gut they bind bile acids, which nudges the liver to pull more cholesterol out of the blood. People mostly look at them for high cholesterol, where the evidence is strong, and analyses of trials found blood glucose improved in people with high cholesterol, along with apolipoprotein B. Most of these effects were small, so the gains were modest.
- Best evidence:
Lactobacillus Casei
Lactobacillus casei is a probiotic bacterium found in the gut and in fermented foods, where it helps break down food and interacts with the immune system. People mostly look at it for immune health, but the evidence is limited: a small study of 28 people found that the inflammation marker CRP changed, though which way is unclear. Other small studies found no clear difference in blood glucose or in immunity during upper respiratory infections.
- Best evidence:
PQQ
PQQ is a compound that helps cells build new mitochondria, the tiny structures that produce their energy. People mostly look at it for fatigue and low energy, and a small study found fatigue symptoms and pain improved, though the evidence is limited. That research involved only 17 people, and a separate tiny study of 10 found no clear difference in blood glucose, so firm conclusions will need larger trials.
- Best evidence:
Aloe Vera
Aloe vera is a succulent plant whose clear inner gel has soothing, anti-inflammatory properties, used on skin and in the mouth. People often look at it for sunburn and mouth care, and for oral health the evidence is moderate: a review found a small improvement in dental health measures. That rests on one small study of 141 people, and pain showed no clear difference.
- Best evidence:
Arachidonic Acid
Arachidonic acid is an omega-6 fatty acid found in cell membranes throughout the body, where it serves as a building block for signaling molecules involved in inflammation and muscle repair. People mostly look at it for body composition and exercise performance, and the evidence is limited: in one small study, anaerobic capacity improved, while body fat showed no clear difference. That research involved only 31 people, so it says little about how results might apply more broadly.
- Best evidence:
Bitter orange
Bitter orange is a citrus fruit whose peel extract contains synephrine, a stimulant-like compound that acts on adrenaline-related receptors. People mostly look at it for weight management, but the evidence is very limited, and research in 86 people found no clear difference in blood glucose. Small trials also found no clear difference in alertness, anxiety symptoms or headaches.
- Best evidence:
Carnosine
Carnosine is a small protein building block made of two amino acids, found in muscle and brain tissue, where it helps buffer acid and protect cells from damage. People with type 2 diabetes have been the focus of most research, and trials found blood glucose improved and beta-cell function, the insulin-making capacity of the pancreas, went up, with moderate evidence for both. Those results come from small studies of about 377 people in total, so they are early findings rather than settled ones.
- Best evidence:
Cornelian Cherry Extract
Cornelian cherry is the tart red fruit of a dogwood-family tree, and its extract is rich in plant compounds such as anthocyanins and other polyphenols that act as antioxidants. In trials, body mass index went down and blood glucose improved, and the evidence for both is moderate. Still, the studies were small, involving a few hundred people at most, so these results are early and need larger trials to confirm.
- Best evidence:
Guduchi
Guduchi is a climbing vine used in Ayurvedic medicine, and its plant compounds appear to influence how immune cells behave. People often look at it for seasonal allergies, and among 75 people with hay fever, symptoms eased and eosinophils, a white blood cell involved in allergic reactions, went down. The evidence is limited, though, and a small trial in diabetic foot ulcers found no clear difference.
- Best evidence:
Guduchi
Guduchi is a climbing herb from India, long used in Ayurvedic medicine and studied for its effects on immune activity. People mainly look at it for seasonal allergies, and research in 75 people found allergy symptoms improved and eosinophils, an immune cell involved in allergic reactions, went down. The evidence is limited, though, and small studies in HIV, sepsis and diabetic foot ulcers found no clear difference.
- Best evidence:
Valerian
Valerian is a flowering plant whose root is made into herbal extracts, and it is thought to work partly through GABA, a calming chemical messenger in the brain. People mostly look at it for sleep quality and insomnia, where the overall evidence is moderate, and small studies found fatigue and insomnia symptoms eased. Still, each study was small, and the insomnia trial enrolled only postmenopausal women, so results may not fit everyone.
- Best evidence:
Cannabidiol (CBD)
Cannabidiol, or CBD, is a non-intoxicating compound from the cannabis plant that interacts with several signaling systems in the brain, including those that help calm overactive nerve activity. People most often look at it for seizures in treatment-resistant epilepsy, and large trials found people had fewer seizures, including fewer drop seizures in Lennox-Gastaut syndrome, with the evidence rated strong. Findings for anxiety were far thinner, coming from small studies with only 57 people in total, so that evidence is limited.
- Best evidence:
Elderberry
Elderberry is the dark purple berry of the Sambucus plant, rich in anthocyanins, plant pigments that have shown antiviral and immune-signaling activity in lab work. People mostly look at it for influenza and other respiratory infections, and the evidence is moderate: in a few small trials of colds, upper respiratory symptoms improved. That rests on only three studies with about 180 people, so it says little about how well it works for flu itself or for anyone outside those groups.
- Best evidence:
Nicotinamide
Nicotinamide is a form of vitamin B3 that cells use to make NAD, a molecule involved in energy production and DNA repair. People mostly look at it for skin cancer, but the evidence is very limited, and a study of 416 people found no clear difference in melanoma risk. The evidence is stronger for acne, where three studies of skin-applied nicotinamide found symptoms improved, though that is a separate question.
- Best evidence:
Serrapeptase
Serrapeptase is a protein-digesting enzyme that may help thin mucus and calm inflammation in tissues such as the sinuses. People mostly look at it for sinus trouble, and the evidence there is limited: trials found nasal mucus production improved. Those studies were small, about 190 people across four trials, and they focused on allergy and ear, nose and throat complaints rather than sinusitis itself.
- Best evidence:
Yarrow
Yarrow is a flowering herb whose leaves and flowers, rich in plant compounds like flavonoids, have long been used in traditional remedies. In a small pregnancy study, inflammation went down, though the evidence is limited, and a kidney disease study found no clear difference in plasma nitrate. Trials involved 140 people at most, and fatigue in people with cancer also showed no clear difference, so conclusions remain very tentative.
- Best evidence:
Ellagic Acid
Ellagic acid is a plant compound found in pomegranates, berries and walnuts, where it acts as an antioxidant and may influence how the body handles sugar and fats. Research has looked mostly at blood glucose, and the evidence is moderate: a review of trials found blood glucose improved. Still, that finding rests on a single small review, and body mass index showed no clear difference across 422 participants, so the picture is far from settled.
- Best evidence:
Garcinia
Garcinia is a tropical fruit whose rind is rich in hydroxycitric acid, a compound thought to influence how the body makes fat. People mostly look at it for weight loss, but the evidence is very limited, and research in 89 people found no clear difference in appetite. Those studies were small, so they leave the question open rather than settling it.
- Best evidence:
Rooibos
Rooibos is a caffeine-free herbal tea from a South African shrub, rich in polyphenols that act as antioxidants. People look at it for heart and metabolic health, and the evidence is limited: one small study of 15 adults found HDL, the good cholesterol, improved. Blood glucose results were mixed and blood pressure showed no clear difference in these tiny studies.
- Best evidence:
TUDCA
TUDCA is a bile acid, a natural compound made from bile salts, that helps protect liver cells and eases stress inside them. People mostly look at it as supportive care in hepatitis C, where the evidence is moderate overall, though the one small study reviewed found that liver cell content went up in only five people. That is very little to go on, and the wider evidence is limited, with a few small studies and no clear difference in blood glucose.
- Best evidence:
Vanadium
Vanadium is a trace mineral found in small amounts in food and water, and in lab work it can mimic some of insulin's actions in cells. People mostly look at it for blood sugar control in obesity, but two small studies with 44 participants found no clear difference, and the evidence is very limited. Even smaller studies of HDL cholesterol and blood pressure also found no clear difference, involving only 14 and 6 people.
- Best evidence:
Thiamine (Vitamin B1)
Thiamine, also called vitamin B1, is a vitamin the body needs to turn food into energy and keep nerves working. Researchers mostly look at it for small blood vessel damage, where the evidence is moderate, and the clearest finding was that premenstrual symptoms improved in one large trial of 344 people. Other findings were thin: blood pressure improved in a tiny diabetes study, and a heart failure trial found no clear difference in walking.
- Best evidence:
Vitamin B12
Vitamin B12 is a vitamin the body needs to keep nerves working, build red blood cells and make DNA, and the risk of running low rises with age. People mostly look at it for low B12 levels, where the evidence is strong, though trials measuring thinking and memory in that group found no clear difference. Studies of depression symptoms also found no clear difference, and the evidence there is very limited.
- Best evidence:
Riboflavin (Vitamin B2)
Riboflavin, or vitamin B2, is a vitamin that helps cells turn food into energy. People mainly look at it for headache after a spinal puncture, but the evidence there is limited and few clear trial results have been reported. A trial of 181 people with migraine found no clear difference in frequency, while four small studies found blood pressure improved.
- Best evidence:
Yacon
Yacon is an Andean root vegetable rich in fructooligosaccharides, a fiber that passes undigested to the gut, where bacteria ferment it. In a small trial of 35 people with obesity, glycemic control improved, though blood glucose itself showed no clear difference, and stool weight also changed in 16 healthy volunteers. The evidence is limited, so these are early signals from small studies rather than firm conclusions.
- Best evidence:
Alpha-GPC
Alpha-GPC is a choline-containing compound that reaches the brain and helps the body make acetylcholine, a chemical messenger central to memory and learning. Most people look at it for Alzheimer's disease, and in one multicenter trial of 261 people with mild to moderate dementia, symptoms improved compared with placebo. That evidence is limited, though, resting on a single study, so it can't say how well the benefit holds up more broadly.
- Best evidence:
Anatabine
Anatabine is a minor alkaloid found in tobacco and other nightshade plants, chemically related to nicotine and sold as a supplement. The research on it is very limited so far: a small study of 20 people found no clear difference in blood pressure or heart rate. That trial was placebo-controlled and mainly looked at markers of muscle damage, so it says little about other reasons people try anatabine.
- Best evidence:
Artichoke Extract
Artichoke extract comes from the leaves of the artichoke plant, and its compound cynarin helps stimulate bile production and flow, which supports digestion. People look at it for general liver health, and studies found liver enzyme readings improved, though the evidence is limited. Elsewhere, results were thin: one tiny study of 18 people saw blood flow go up, while larger studies found no clear difference in HDL cholesterol or blood glucose.
- Best evidence:
Black Chokeberry
Black chokeberry, also called aronia, is a dark purple berry rich in anthocyanins, plant pigments that work as antioxidants in the body. In people with high cholesterol, markers of oxidative stress went down, though the evidence is limited. That finding came from just 25 people, and total cholesterol showed no clear difference. Blood glucose didn't clearly change either, so the evidence stays very limited.
- Best evidence:
Shilajit
Shilajit is a tar-like resin from mountain rock, used for centuries in Ayurvedic medicine and thought to influence hormones involved in male fertility. People mostly look at it for low sperm count, and the evidence is limited: in a small trial of 60 men, follicle-stimulating hormone went up. Luteinizing hormone showed no clear difference, and one small study of 45 people found antioxidant enzymes went up, so the picture is early.
- Best evidence:
Terminalia Arjuna
Terminalia arjuna is a tree whose bark has long been used in Ayurvedic medicine, valued for plant compounds that may act as antioxidants. In people with coronary artery disease, heart size went down and the heart's pumping strength, measured as ejection fraction, improved, though the evidence is limited. Each finding came from a single study of just 10 people, and a review in stable angina found no clear difference in exercise tolerance.
- Best evidence:
Benfotiamine
Benfotiamine is a fat-soluble form of vitamin B1, a nutrient cells use to turn food into energy. People mostly look at it for diabetic nerve problems, but the evidence is very limited: one study of 82 people found no clear difference in advanced glycation end products, a marker of sugar-related damage. Small studies of 63 to 67 people also found no clear difference in HbA1c, HDL or blood pressure.
- Best evidence:
Copper
Copper is an essential mineral that helps enzymes handle iron, build connective tissue and make the pigment melanin. People with celiac disease can run low, which is why it draws attention there, though the evidence for that use is limited. The strongest research came from copper deficiency, where blood copper and ceruloplasmin levels went up.
- Best evidence:
Ornithine
Ornithine is an amino acid the body makes as part of the urea cycle, the process that helps clear ammonia from the blood. Researchers have looked at it for stress hormones, but the evidence is limited: a single crossover trial in 27 people found mixed results for cortisol. Other small work in 15 people also found mixed results for ammonia and no clear difference in blood pressure, so the picture is thin.
- Best evidence:
Stinging Nettle
Stinging nettle is a leafy plant whose extracts contain compounds that may dampen prostaglandin activity and histamine-driven inflammation in the body. People mostly look at it for hay fever, and in a small trial of freeze-dried nettle, allergy symptoms improved, though the evidence is limited. That result rests on a single short study with fewer than 100 people, so it is far from settled, and nettle cream and nettle stings showed no clear difference for osteoarthritis pain.
- Best evidence:
Vitamin A
Vitamin A is a fat-soluble vitamin that supports vision, immune defenses, and the health of skin and other linings. People mostly look at it for infant health, and with moderate evidence, trials found diarrhea symptoms improved and infant death risk fell. The effects were small, and the death-risk findings came from six trials of about 1,165 very-preterm or low-birth-weight babies, so they may not apply to every infant.
- Best evidence:
7,8-Dihydroxyflavone
7,8-Dihydroxyflavone is a plant-derived flavonoid that switches on TrkB, the receptor for BDNF, a protein that helps brain cells grow, connect and survive. People mostly look at it for memory and age-related cognitive decline, and in rodents it consistently improved spatial memory, long-term memory and learning, though the evidence is limited. Nearly all of this work was in mice and rats, so what it does for memory in people remains unstudied here.
- Best evidence:
Black Ginger
Black ginger, also called Thai ginseng, is a root related to common ginger that is rich in plant compounds called flavonoids, which may influence the body's antioxidant defenses. In a study of 45 people, levels of antioxidant enzymes went up, though the evidence is limited. For exercise, a small study of 17 people found no clear difference in sprint or endurance performance, so the research is thin and early.
- Best evidence:
CDP-Choline
CDP-choline, or citicoline, is a compound the body uses to build phospholipids, the fats in brain cell membranes, and to support acetylcholine. People mostly look at it for stroke recovery, where the evidence is moderate, and small trials in older adults found better memory and modest gains in attention. Those studies were small, with about 100 people or fewer, so the evidence behind them is limited.
- Best evidence:
Chaste tree
Chaste tree is a shrub whose dried berries are used as an herbal extract, thought to act on the brain's dopamine and prolactin signaling, which helps steer the menstrual cycle. People mostly look at it for premenstrual syndrome, and the evidence is strong overall: in a trial of 405 women, breast tenderness improved, and anxiety symptoms also eased in a smaller group. Those anxiety findings came from only 64 women, so the evidence there is limited, and the breast tenderness result rests on a single study.
- Best evidence:
Cordyceps
Cordyceps is a medicinal fungus long used in traditional medicine as a tonic for the kidneys and for energy. People mostly look at it for end-stage kidney disease, and the evidence is moderate: studies found blood urea nitrogen, a waste product the kidneys normally clear, went down. Those studies were small, though, and evidence for other uses is thin; in cyclists, one small trial found no clear difference in endurance.
- Best evidence:
Iodine
Iodine is a trace mineral the thyroid gland uses to build its hormones, and too little causes hypothyroidism. Most people look at it for thyroid health, where the evidence is strong that it is essential, though small trials found blood T3 went down in healthy men and T4 went down in people with Hashimoto's disease. Those hormone findings are limited, coming from small studies, including one of just 32 men.
- Best evidence:
Laughter
Laughter is a natural burst of voice and breathing that works the diaphragm and face muscles and is tied to the body's stress responses. People mostly look at it for mood during breast cancer, where the evidence is strong: depression symptoms eased among 304 people and anxiety symptoms eased among 128. Those results come only from people with breast cancer, so they may not apply elsewhere.
- Best evidence:
Leucine
Leucine is an essential amino acid that signals muscle cells to build new protein. People mostly look at it for age-related muscle loss, where it may help overcome the blunted muscle response of aging, and the evidence is moderate across about 600 participants. Other findings are thinner: body fat and liver enzymes showed no clear difference in very limited research on 26 people.
- Best evidence:
MSM
MSM, short for methylsulfonylmethane, is a sulfur-containing compound that the body can use to build connective tissue like cartilage, and it may also have mild anti-inflammatory and antioxidant effects. Most people look at it for osteoarthritis, and a small trial found knee osteoarthritis symptoms improved, though the evidence is limited. That study was small, at 148 people, so the picture is still preliminary and needs larger trials to confirm it.
- Best evidence:
Piracetam
Piracetam is a lab-made compound from the racetam family, thought to influence how brain cells communicate. People mostly look at it for dementia, but the evidence there is very limited: a single small study of 24 people found no clear difference in cognition. Broader research on cognitive impairment looked more encouraging, with five studies covering 213 people finding less cognitive decline, though those studies were modest in size and involved a different group.
- Best evidence:
Prenatal Vitamins
Prenatal vitamins are multivitamin and mineral blends made for pregnancy, covering nutrients the body needs to build a baby's tissues. People mostly look at them for healthy birth weight, and two reviews of trials in lower-income countries found birth weight changed, though the direction was unclear. That evidence is moderate at best; executive function improved in children, but the evidence is limited, and anemia risk showed no clear difference.
- Best evidence:
Vitamin B5 (Pantothenic Acid)
Vitamin B5, or pantothenic acid, is a B vitamin the body uses to make coenzyme A, which helps release energy from food and build adrenal hormones. People look at it for adrenal support, where the evidence is limited, while stronger trial findings came in deficiency, where symptoms went down and blood levels went up. Skin results, such as fewer acne lesions and better hydration, were moderate in strength and came from mid-sized studies.
- Best evidence:
Exogenous Ketones
Exogenous ketones are ketone bodies made in a lab and swallowed, giving the body a fuel the liver normally produces during fasting or very low-carb eating. People look at them for metabolic health, and studies covering 586 participants found blood glucose improved, with moderate evidence, though the effect was small. For athletes the picture was weaker: two reviews found no clear difference in aerobic exercise performance, on very limited evidence.
- Best evidence:
Korean black raspberry
Korean black raspberry is a dark berry rich in plant pigments called anthocyanins, which work as antioxidants in the body. The evidence is limited: in a small group of 15 people, levels of the body's antioxidant enzymes went up. Blood glucose showed no clear difference in an even smaller group of nine people, so the evidence there is very limited and far from settled.
- Best evidence:
Manganese
Manganese is a trace mineral that helps build bone and powers enzymes such as manganese superoxide dismutase, which protects cells from oxidative damage. The evidence is strongest in people with low manganese, where studies found blood manganese levels and MnSOD levels went up. Findings for bone density, oxidative stress markers, PMS symptoms and wound closure are only moderate, and those studies were small to moderate in size.
- Best evidence:
Passionflower
Passionflower is a climbing vine whose leaves and flowers are used in herbal extracts, and it is thought to raise the activity of GABA, a calming chemical messenger in the brain. People mostly look at it for generalized anxiety, and across six studies anxiety symptoms improved, with a moderate-sized effect and moderate evidence overall. Those studies were small, together enrolling only 66 people, and some tested it alongside other medicines or in a dental-visit setting, so the results say little about long-term everyday use.
- Best evidence:
Pomegranate seed oil
Pomegranate seed oil is a plant oil pressed from pomegranate seeds, and like other dietary oils the body absorbs it as a source of fat. People mostly look at it for metabolic health, and the evidence is limited: in a small study of 30 people, HDL, the so-called good cholesterol, rose. In 51 people with high cholesterol, body fat and blood sugar control showed no clear difference, and that evidence is very limited.
- Best evidence:
Capsaicin
Capsaicin is the compound that gives chili peppers their heat, and applied to a sore area it wears down substance P, a messenger that nerve endings use to carry pain signals. People mostly look at it for pain, and the evidence is strong for general pain relief and moderate for nerve pain, diabetic neuropathy and low back pain. Beyond pain, evidence is limited: one small study of 12 people found blood glucose improved.
- Best evidence:
Hemp Protein
Hemp protein is a powder made from ground hemp seeds, supplying plant protein the body breaks down into amino acids for building and repairing tissue. Eczema is the area with the most research, and a small trial of 16 people found eczema symptoms improved, though the evidence is limited. Skin quality showed no clear difference, and HDL cholesterol showed no clear difference in 86 people, so evidence beyond that is very limited.
- Best evidence:
Molybdenum
Molybdenum is an essential trace mineral that helps enzymes break down sulfites and process purines. The evidence is strongest in people with a molybdenum deficiency, where studies found blood molybdenum levels went up and sulfite levels went down. Findings for sulfite sensitivity symptoms were moderate, while reports of lower esophageal cancer and cavity risk came from small studies, so that evidence is limited.
- Best evidence:
Prebiotics
Prebiotics are plant fibers that the body can't digest but that feed the beneficial bacteria living in your gut. People mostly look at them around Clostridioides difficile infection, a gut infection that can follow antibiotics, and the evidence there is moderate, covering about 600 people. Elsewhere it is thinner: very limited studies found no clear difference in irritable bowel pain or bloating, or in body mass index in fatty liver disease.
- Best evidence:
Propolis
Propolis is a resin bees make from plant sap and wax to seal their hives, and it has antiviral and antimicrobial properties. People mostly look at it for cold sores, but the evidence there is limited, and little research has shown clear results so far. The best-supported finding lies elsewhere: a review of over 1,000 adults found blood glucose improved, while blood pressure and body fat showed no clear difference.
- Best evidence:
Saw Palmetto
Saw palmetto is an extract from the berries of a small palm, thought to slow an enzyme that turns testosterone into DHT and to calm inflammation. Most people look at it for urinary symptoms linked to an enlarged prostate, and the evidence is moderate: across seven studies with about 2,000 people, symptoms eased. The improvement was small, and one study of 32 people found no clear change in DHT.
- Best evidence:
Silymarin
Silymarin is a group of plant compounds from milk thistle seeds that act as antioxidants and are studied for their role in protecting liver cells. People mostly look at it for nonalcoholic steatohepatitis, and combined trials found liver enzyme levels improved, with moderate evidence behind that. The studies were small, though, six trials with 437 people, and in fatty liver research body mass index and HDL cholesterol showed no clear difference, with very limited evidence.
- Best evidence:
Essential fatty acid (EFA)
Essential fatty acids are omega-3 and omega-6 fats the body cannot make, so they come from food, where they build cell membranes and feed signaling molecules involved in inflammation. People most often look at them for dry eye, and reviews of clinical studies found steadier tear film and eased symptoms, though the evidence is limited. Those were narrative reviews, not large trials, and results for ADHD were small and inconsistent.
- Best evidence:
Fecal Transplant
A fecal transplant moves gut bacteria from a healthy donor's stool into another person's intestines, reshaping the microbes that help digest food. People mostly look at it for irritable bowel syndrome, and the evidence is limited: in a small group of 164 people, bloating improved. Abdominal pain showed no clear difference, and the evidence there is very limited, so the picture is still early.
- Best evidence:
Idebenone
Idebenone is a lab-made relative of coenzyme Q10 that can pass electrons inside mitochondria, the parts of cells that make energy. People mostly look at it for mitochondrial conditions, and the evidence is moderate for Leber's hereditary optic neuropathy, where trials found visual acuity improved, especially in people whose eyes differed in vision at the start. Results in Friedreich's ataxia were mixed, and most other findings come from lab work.
- Best evidence:
King of Bitters
King of Bitters is a bitter-tasting herb, also called Andrographis, whose main active compound, andrographolide, is studied for its effects on inflammation and immune activity in the body. People mostly look at it for the common cold, and a trial of 316 people found upper respiratory symptoms improved, with moderate evidence, while a smaller trial found sore throat symptoms eased. Each result comes from a single study, and a small HIV trial found no clear difference in CD4 immune cells, so the picture is still thin.
- Best evidence:
Lactobacillus acidophilus
Lactobacillus acidophilus is a friendly bacterium that lives naturally in the gut and vagina, where it produces lactic acid and helps keep the microbial community in balance. Most people look at it for antibiotic-associated diarrhea, and human trials found fewer cases of it, with moderate evidence behind that result. Many of those trials used it alongside other Lactobacillus strains, and research on gut inflammation, immunity and cholesterol comes mostly from animal or lab studies.
- Best evidence:
Microlactin
Microlactin is a milk-derived protein preparation made from the milk of hyperimmunized cows, and it is thought to influence inflammation-related signaling in the body. People mostly look at it for osteoarthritis, and one small trial of 31 people found their joint symptoms improved. The evidence is limited, since that is a single short study, and the small trials on cholesterol and blood pressure were too tiny to draw firm conclusions.
- Best evidence:
Sea Buckthorn
Sea buckthorn is a shrub whose orange berries are rich in carotenoids, vitamin C and fatty acids, and its oil is used as a supplement that supplies these nutrients to the body. The strongest finding so far is for dry eye, where a small trial found people's symptoms improved, though the evidence is limited. That was one study of 86 people, and other small studies found a drop in carbohydrate absorption and no clear difference in a blood marker of inflammation.
- Best evidence:
Terminalia Chebula
Terminalia chebula is the dried fruit of a tree used in Ayurvedic medicine, rich in polyphenols that act as antioxidants. People look at it mostly for oral health, and three trials found a mouthwash made from it worked comparably to chlorhexidine for dental plaque, gum inflammation and cavity-linked bacteria. Evidence for joints, blood sugar and skin is limited, and much of it comes from animal or lab work.
- Best evidence:
Theaflavins
Theaflavins are polyphenol antioxidants that form when tea leaves are fermented into black tea. Little research exists, but a small study of 18 people found that the stress hormone cortisol went down during muscle recovery, though the evidence is limited. In 102 people with high cholesterol, LDL and HDL showed no clear difference, and that evidence is very limited.
- Best evidence:
Vitamin B6
Vitamin B6 is a water-soluble vitamin that helps enzymes make brain chemicals like serotonin and dopamine and break down amino acids. People mostly look at it for nausea in pregnancy, where the evidence is strong, and for premenstrual syndrome, where five studies covering about 1,460 people found symptoms improved. The PMS effect was small, though, and the evidence there is moderate.
- Best evidence:
5-HTP
5-HTP is a compound the body makes from the amino acid tryptophan and then converts into serotonin, a chemical messenger that helps shape mood, sleep, and appetite. Most people look at it for appetite control, and the evidence is moderate: in people with obesity, appetite went down, and weight loss followed the smaller appetite. The studies were small, though, and the weight findings remain limited.
- Best evidence:
Chlorogenic Acid
Chlorogenic acid is a natural plant compound, found in coffee beans and some fruits and vegetables, that acts as an antioxidant in the body. People mostly look at it for blood pressure, and a small trial in people with high blood pressure found their readings improved, though the evidence is limited. That rests on a single study of 28 people, and a review of cognition across 243 participants found no clear difference.
- Best evidence:
Japanese Knotweed
Japanese knotweed is a plant whose roots are rich in resveratrol and related plant compounds, which act as antioxidants in the body. People mostly look at it for metabolic health, but the evidence is very limited: one small study of 20 people found no clear difference in blood glucose or overall glycemic control. That is far too little to draw firm conclusions, so it remains an open question whether it helps at all.
- Best evidence:
Jiaogulan
Jiaogulan is a climbing vine whose leaves contain gypenosides, plant compounds thought to influence how the body handles sugar and fat. People mostly look at it for blood sugar in type 2 diabetes, and moderate evidence from a study of 49 people found blood glucose came down. Studies so far are small, and a 56-person fatty liver study found better blood sugar control too, but that evidence is limited.
- Best evidence:
Lactase Enzyme
Lactase is an enzyme your small intestine makes to break down lactose, the main sugar in milk, and supplements supply extra of it. People mostly look at it for lactose intolerance, and the evidence is strongest for bloating, which improved in trials, while abdominal pain also eased with moderate evidence. Those studies were fairly small, with 66 and 85 participants, so the findings are a starting point rather than the final word.
- Best evidence:
Lactoferrin
Lactoferrin is an iron-binding protein found in milk and tears that helps regulate immune defenses and inflammation. People mostly look at it for dry eye, where it may support the surface of the eye, though the evidence there is limited and comes from about 250 participants. Firmer findings lie elsewhere: hemoglobin and iron levels went up in iron deficiency anemia, and respiratory infections went down, with strong evidence for each.
- Best evidence:
Naringenin
Naringenin is a flavanone, a plant pigment abundant in grapefruit and other citrus, which can influence enzymes and transporters that handle food compounds and medicines. Grapefruit juice containing it raised blood levels of several medications by slowing an intestinal enzyme, and in one six-month trial postmenopausal women's arterial stiffness eased. The evidence is limited, though: other grapefruit compounds may drive the drug effect, and most heart and cholesterol findings come from animal or lab studies.
- Best evidence:
Nattokinase
Nattokinase is an enzyme from natto, a fermented soybean food, that may help break down fibrin, a protein involved in blood clots. People mostly look at it for clot-related concerns like deep vein thrombosis, and the evidence is limited: a small trial of 45 people found levels of clotting factors VII and VIII went down. Another small trial saw blood pressure improve, but studies so far have been few and small.
- Best evidence:
Salidrosides
Salidroside is a compound from the Rhodiola rosea plant that appears to influence the body's stress-response system. People mostly look at it for fatigue and stress resilience, and the evidence is limited: human trials found anti-fatigue effects from Rhodiola extracts rich in salidroside. Those trials tested the whole extract, not salidroside alone, and most other research has been in animals or cells.
- Best evidence:
Aged Garlic Extract
Aged garlic extract is made by soaking sliced garlic for months, which turns its harsh compounds into gentler sulfur compounds that may help blood vessels relax. The evidence is strongest for blood pressure, where a meta-analysis found systolic pressure fell by about 8 mmHg in people with high blood pressure. Those results come from roughly 550 people with hypertension, and the evidence for cholesterol was more limited.
- Best evidence:
Amla
Amla, also called Indian gooseberry, is a tart fruit used in Ayurvedic tradition and rich in vitamin C and polyphenols, which act as antioxidants in the body. People with type 2 diabetes have looked to it for blood sugar, and the evidence is limited: blood glucose improved, and so did HDL cholesterol, in research involving 32 people. That is a small group, so these findings say little about how well amla works broadly.
- Best evidence:
Bilberry
Bilberry is a dark blue berry rich in anthocyanins, pigments that act as antioxidants and help support small blood vessels and blood flow, including in the eye. People mostly look at it for eye health, such as elevated eye pressure, where the evidence is limited, though trials found focusing ability improved after long screen sessions. Those studies were fairly small, so the picture is still early.
- Best evidence:
Boswellia
Boswellia is a resin from the Boswellia tree whose boswellic acids block 5-lipoxygenase, an enzyme that helps produce inflammatory leukotrienes in the body. People look at it mainly as supportive care around brain tumors, where it may reduce swelling, and the reported result was a smaller tumor size, though the evidence is limited. That finding came from a single person, and in osteoarthritis, C-reactive protein showed no clear difference in 98 people.
- Best evidence:
Butcher's Broom
Butcher's broom is an evergreen shrub whose roots contain ruscogenins, plant compounds thought to tighten vein walls and calm inflammation in the legs. People mostly look at it for chronic venous insufficiency, and a placebo-controlled trial found that signs of the condition improved. That evidence is limited, though, since it came from one small study of 110 people, so it is far from settled.
- Best evidence:
Cissus Quadrangularis
Cissus quadrangularis is a climbing plant related to grapevines, and its stems have long been used in traditional medicine for bone and joint complaints. Research is thin: in a small group of people with obesity, oxidative stress markers went down while creatinine, a marker of kidney function, went up, and in a tiny osteoarthritis study blood pressure showed no clear difference. The evidence is limited to very limited, so these results are early.
- Best evidence:
Cyanidin
Cyanidin is a pigment in red, purple and blue plants, such as berries and black rice, that acts as an antioxidant and helps shield plant cells from stress. People mostly look at it for blood sugar control, and the evidence is limited: lab and animal studies found it helped cells take up glucose and lowered blood glucose in diabetic rodents. Almost all of this work was in cells and animals, so how well it carries over to people remains unclear.
- Best evidence:
ECA
ECA is a combination of ephedrine, caffeine and aspirin, a stimulant blend that revs up the nervous system and nudges the body to burn more energy. In people with obesity, research found no clear difference in blood glucose or blood pressure, though the evidence is very limited. Only 24 people took part, so these findings are small and can't say much beyond that group.
- Best evidence:
Fennel Essential Oil
Fennel essential oil is an aromatic oil from the fennel plant, rich in compounds like anethole. The main human research looks at diarrhea-predominant irritable bowel syndrome, where one trial of 121 people found symptoms eased about twice as much with a curcumin and fennel oil blend as with placebo, though the evidence is limited. Since the oil was tested alongside curcumin, its own effect is unclear, and most other findings come from animal or lab studies.
- Best evidence:
GlyNAC
GlyNAC combines glycine and N-acetylcysteine, two building blocks the body uses to make glutathione, a key antioxidant. People mostly look at it to restore low glutathione, and small trials in older adults with HIV and in people with type 2 diabetes found levels were corrected and oxidative stress markers fell. The evidence is limited: only about 36 people took part, the trials were small or open-label, and in the HIV trial benefits faded once supplementation stopped.
- Best evidence:
Horny Goat Weed
Horny goat weed is a plant used in traditional medicine whose main compound, icariin, appears to support bone by encouraging bone-building cells and slowing the cells that break bone down. Most people look at it for osteoporosis, and the evidence is moderate: studies found bone mineral density improved, including in a 24-month trial of late postmenopausal women. Those studies were small, only two contributed to that finding, and results mostly apply to postmenopausal women, so the evidence is far from settled.
- Best evidence:
Nicotinamide Adenine Dinucleotide
NAD+ is a molecule found in every cell, where it helps turn food into energy and supports DNA repair and cell signaling. People mostly look at it, usually through precursors like nicotinamide riboside, to slow the effects of aging, and small human trials found blood and muscle NAD+ levels reliably went up, though the evidence is limited. Those studies were small, and whether higher levels translate into healthier aging remains unclear, since most other findings come from animal or lab work.
- Best evidence:
Oxiracetam
Oxiracetam is a lab-made compound from the racetam family that is thought to influence AMPA receptors, which help nerve cells signal to each other and form memories. People mostly look at it for dementia, and across four small studies the evidence was moderate that cognitive decline improved. A separate look at day-to-day functioning found no clear difference, and that evidence is very limited, so the picture is far from settled.
- Best evidence:
Red Yeast Rice
Red yeast rice is rice fermented with a yeast that makes monacolin K, a natural form of lovastatin that slows an enzyme the liver uses to build cholesterol. Most people look at it for high cholesterol, where the evidence is strong, and in trials of people with type 2 diabetes, LDL cholesterol fell. Apolipoprotein A showed no clear difference, though that evidence is very limited.
- Best evidence:
Senna
Senna is a plant-based laxative whose natural compounds, called anthraquinone glycosides, stimulate the nerves in the colon wall, which speeds up muscle movement and draws fluid into the gut. People mostly look at it for constipation, and trials found symptoms improved, including in older adults and in cancer patients taking opioids. Those studies were very small, just 30 people across two trials, so the evidence for constipation is limited, though other research found it made the intestines move more.
- Best evidence:
Vitamin K2 (MK-7)
Vitamin K2 as MK-7 is a form of vitamin K that activates proteins, such as osteocalcin in bone, which help direct calcium where the body needs it. The evidence is strongest for bone health: trials found much less inactive osteocalcin, and bone density in the spine and femoral neck declined less than with placebo. Still, the evidence for bone density is moderate, and the studies were moderate in size.
- Best evidence:
Celery seed extract
Celery seed extract is a concentrated preparation from celery seeds, which contain plant compounds thought to help blood vessels relax. The strongest evidence is for blood pressure, where a review of randomized trials found small but consistent reductions, and the evidence is moderate. Improvements in blood sugar were also small, while findings for LDL and HDL cholesterol were modest and the evidence limited.
- Best evidence:
Chlorophyll
Chlorophyll is the green pigment plants use to capture sunlight, and supplements usually contain chlorophyllin, a water-soluble copper-based form. The best-supported finding involves aflatoxin, a mold toxin: in a trial in China, people taking chlorophyllin had 55% lower levels of aflatoxin-DNA damage markers in their urine than those given placebo. Still, the evidence is limited, since most supporting studies were in animals or the lab.
- Best evidence:
Clove
Clove is the dried flower bud of a tropical tree, and its main active compound, eugenol, numbs tissue and disrupts microbes. People mostly look at it for dental pain, and the evidence is moderate: small trials found a clove gel eased needle-stick pain in the mouth about as well as a common numbing gel. Most other claims, such as germ-killing or blood sugar effects, come from lab and animal work.
- Best evidence:
Danshen
Danshen is the dried root of Salvia miltiorrhiza, a plant used in Chinese medicine whose compounds appear to affect blood vessels and platelets. People mostly look at it for heart health, and trials of a danshen formula found fewer angina episodes and better ECG readings alongside standard care, with moderate evidence. Those studies had methodological limits, though, and most other danshen research is animal or lab work.
- Best evidence:
Date Palm Pollen
Date palm pollen is the pollen of male date palm trees, a traditional Middle Eastern remedy that contains antioxidant plant compounds with hormone-like activity. People mostly look at it for male fertility, and two small controlled trials in infertile men found better sperm count, motility, and shape. Still, the evidence is limited, since most of the research has been done in animals rather than people.
- Best evidence:
Devil's Claw (Harpagophytum procumbens)
Devil's claw is a southern African herb whose root holds harpagoside, a compound thought to calm inflammation in joints and muscles. People mostly look at it for chronic low back pain, and a Cochrane review found strong evidence of short-term pain relief compared with placebo, with hints that people needed less rescue pain medication. The trials were few and small, though, and the evidence for sudden-onset back pain is limited.
- Best evidence:
Dihydroberberine
Dihydroberberine is a modified form of berberine, a plant compound that nudges the enzyme AMPK, which helps cells manage energy and blood sugar. In people with type 2 diabetes, trials found fasting blood sugar, HbA1c and insulin resistance all fell, with HbA1c dropping about as much as it did with metformin, and the evidence is moderate. Each finding rests on a few hundred people at most, and the evidence for smaller waists in metabolic syndrome is only limited.
- Best evidence:
Evening Primrose Oil
Evening primrose oil, pressed from a wildflower's seeds, is rich in gamma-linolenic acid, an omega-6 fatty acid the body uses in skin health and inflammation signaling. People mostly look at it for breast pain, where the evidence is moderate but mixed, and some women reported benefit. In pregnancy studies, cervix readiness went up, but HDL cholesterol and infant birth weight showed no clear difference.
- Best evidence:
Hederagenin
Hederagenin is a plant compound found in ivy leaves and Clematis roots, studied mainly for its effects on inflammation. The evidence is limited, but in rodents and cell studies it dampened NF-κB inflammatory signaling and lowered inflammatory messengers, and in Alzheimer's mice it improved memory and thinking tests. Most of this work was in animals or lab cells, so how it applies to people is unclear.
- Best evidence:
Kudzu
Kudzu is a vine from East Asia whose root holds isoflavones, plant compounds that can act a little like estrogen in the body. People mostly look at it for menopause, and a small trial of 127 people found thinking and memory scores improved, though the evidence is limited. The same small trial found no clear difference in apolipoprotein B, a blood fat marker, so firm conclusions must wait.
- Best evidence:
Moringa
Moringa is a leafy tree whose leaves and pods are eaten as a nutrient-dense food, rich in vitamins, minerals and plant compounds. People mostly look at it to support breast milk production, where the evidence is moderate across about 300 participants. Elsewhere it is limited: a small study of 20 people with asthma found better lung function, and tiny studies saw improved blood glucose and skin dryness.
- Best evidence:
Oleamide
Oleamide is a fatty compound the body makes naturally, which builds up in spinal fluid during sleep deprivation and appears to act on calming brain signals. People mostly look at it for sleep, and in rodents it made animals fall asleep sooner and sleep longer. No human trials have been run, so the evidence is limited, and most other findings come from animal or lab work.
- Best evidence:
Omega-6 Fatty Acids
Omega-6 fatty acids are essential fats, such as linoleic acid, that the body cannot make and uses to build cell membranes and signalling molecules involved in inflammation. Most people look at them for heart health, and trials found that replacing saturated fat with linoleic acid lowered LDL cholesterol, with higher intake linked to fewer cardiovascular events. The evidence is moderate, though some cholesterol findings came from cell studies, and the benefits applied when omega-6 replaced saturated fat.
- Best evidence:
Palmatine
Palmatine is a plant alkaloid related to berberine, found in herbs such as Coptis and Corydalis. In lab tests, it blocked acetylcholinesterase, an enzyme that breaks down a memory-related brain messenger, at very low concentrations, second only to berberine among similar compounds, though the evidence is very limited. Almost all the research is lab or animal work, so how it acts in people is unknown.
- Best evidence:
Phenylpiracetam
Phenylpiracetam is a lab-made relative of piracetam, a compound thought to influence chemical signaling between brain cells. People mostly look at it for thinking and memory, and in two small trials in people with stroke, cognition improved, though the evidence is limited. Those studies were small, and the results apply mostly to people with brain conditions rather than healthy adults, so they say little about everyday sharpness.
- Best evidence:
Phlebodium aureum
Phlebodium aureum is a tropical fern, also known as Polypodium leucotomos, whose extract is rich in plant antioxidants that help cells cope with oxidative stress. Most people look at it for dementia, but the evidence is limited: one small trial in 45 people found that blood flow in the brain went up. That is a single pilot study, so it says little about memory or thinking, and it can't show lasting benefit.
- Best evidence:
Piperine
Piperine is the pungent compound in black pepper, thought to slow how fast the body clears some substances so more reaches the blood. People mostly look at it to boost curcumin absorption, and the evidence is moderate: curcumin levels rose sharply in a small study of healthy volunteers, and turmeric with piperine outperformed turmeric alone in dialysis patients. Most findings come from curcumin combinations, so they say little about piperine alone.
- Best evidence:
Polygala Tenuifolia
Polygala tenuifolia is a plant whose root has long been used in traditional Chinese herbal medicine, and its compounds are thought to influence nerve cells. People look at it for thinking skills with age, and the evidence is limited: one small trial of 106 older adults found cognitive decline improved. A separate study in 53 healthy people found no clear difference in memory, so the picture rests on very few, small trials.
- Best evidence:
Type-II Collagen
Type-II collagen is the main structural protein in cartilage, the cushioning tissue that lines your joints, and supplements usually contain it in a form meant to interact with the immune system. People mostly look at it for osteoarthritis, and the evidence is limited: in a small group of about 259 people, joint symptoms improved. Those studies were small, so the findings are early, and in rheumatoid arthritis, markers such as C-reactive protein and immunoglobulin A showed no clear difference.
- Best evidence:
Vinpocetine
Vinpocetine is a compound made from a substance in the periwinkle plant, thought to widen small blood vessels in the brain and protect nerve cells. People mostly look at it for chronic problems with blood flow to the brain, and the evidence is moderate: small studies found a slight improvement in thinking in vascular dementia, along with better everyday functioning and sense of well-being in older adults. Most of that research was small and limited, and one memory finding came from a tiny study in healthy volunteers, so the results are hard to generalize.
- Best evidence:
Astragalus
Astragalus is a herb, used in traditional Chinese medicine, that is thought to influence immune function. People mostly look at it for support during chemotherapy, and the evidence for that use is moderate, drawing on about 1,200 participants. Beyond that, the findings are thinner: one small trial of 41 people found nasal congestion eased in seasonal allergies, while a 40-person study found no clear difference in telomere length.
- Best evidence:
B Vitamins
B vitamins are a family of eight water-soluble nutrients, including thiamine, folate and B12, that help cells turn food into energy and keep nerves and blood healthy. People most often look at them for support during recovery from alcohol use disorder, since heavy drinking depletes these vitamins, especially thiamine, and the evidence for this use is strong. Folic acid lowered homocysteine, but large reviews found no change in heart disease events or general cognition.
- Best evidence:
Bhringaraj
Bhringaraj is a leafy herb, also called false daisy, used for centuries in Ayurvedic tradition, where it is best known as a hair and liver tonic. In people with high blood pressure, research found blood pressure improved and urine output went up, though the evidence is limited. Only about 60 participants were involved, so these results are early and can't say much about how well it works more broadly.
- Best evidence:
Black Seed Oil
Black seed oil comes from the seeds of Nigella sativa, and its main compound, thymoquinone, has anti-inflammatory and airway-relaxing effects. People most often look at it for asthma, though the evidence there is limited, based on about 400 participants. The stronger findings lie elsewhere: meta-analyses found lower LDL and total cholesterol, along with lower fasting blood glucose and HbA1c.
- Best evidence:
Bushman's Hat
Bushman's Hat is a succulent plant from southern Africa, traditionally chewed by hunters to take the edge off hunger. In a small group of 49 people with overweight, blood bilirubin went up, though the evidence is limited, and appetite showed no clear difference. That is a very thin base, so it says little about whether the plant lives up to its reputation.
- Best evidence:
Chaga
Chaga is a dark fungus that grows on birch trees and is traditionally brewed as a tea, containing polyphenols, melanin, and beta-glucans that give it antioxidant properties. The evidence is limited, but lab studies found chaga extracts slowed the growth of several cancer cell types, and animal studies found tumors grew less. No human trials have tested this, though, and one case report linked very heavy chaga use to kidney damage from its oxalates.
- Best evidence:
Collagen Peptides
Collagen peptides are short chains of amino acids broken down from the collagen in animal connective tissue, and they supply the building blocks your body uses to make its own skin, joint, and nail proteins. People mostly look at them for skin health and aging, and a pooled analysis of randomized trials found skin elasticity improved, with moderate evidence behind it. The improvement was small, though, so it's best seen as a modest benefit rather than a dramatic one.
- Best evidence:
Dong Quai
Dong quai is the root of Angelica sinensis, an herb long used in traditional Chinese medicine, with plant compounds that appear to relax uterine muscle. Most people look at it for menopausal symptoms, and trials found no clear difference from placebo in hot flashes, vaginal changes or overall symptoms. Studies were small, so the evidence is only moderate, and its other suggested uses rest mostly on animal or lab work.
- Best evidence:
Electrolytes
Electrolytes are minerals such as sodium and potassium that carry an electrical charge, helping nerves, muscles and fluid balance work. People mostly look to them for staying hydrated, and the evidence is strong; in exercise trials, electrolyte drinks helped people keep fluid and blood volume better than plain water. Most of that research involved athletes, with the clearest benefits in exercise lasting hours, and evidence for cramps or blood pressure is limited.
- Best evidence:
Feverfew
Feverfew is a traditional medicinal herb whose leaves have long been used in herbal remedies, and it is thought to work by dampening prostaglandins and the release of serotonin from platelets. People mostly look at it for migraine, but across four studies with 406 people, the evidence was very limited and found no clear difference in how often migraines came or how long they lasted. Some of the research was small, so the evidence is too thin to say whether it helps.
- Best evidence:
Haskap Berry
Haskap berry is the tart blue fruit of the honeysuckle plant Lonicera caerulea, rich in anthocyanin pigments that work as antioxidants. People mostly look at it for endurance, and in a small trial of 30 male runners, 5 km times were about 21 seconds faster and time to exhaustion was 20 seconds longer. The evidence is limited, though, and most other research has been in animals or lab dishes.
- Best evidence:
Japanese raisin tree
Japanese raisin tree (Hovenia dulcis) is a tree whose fruit and seeds are used as an extract, rich in a plant compound called dihydromyricetin that appears to influence how the liver handles alcohol and fat. People mostly look at it for hangovers, and small crossover trials found symptom scores and stomach upset eased and blood alcohol was lower early on, though one placebo-controlled trial found no clear drop in overall hangover severity. The evidence is limited, since the human studies were small and most of the wider work was in animals or the lab.
- Best evidence:
Lacticaseibacillus paracasei
Lacticaseibacillus paracasei is a friendly bacterium found in fermented foods like kefir and in the human gut, where it helps shape the community of microbes living there. Research has centered on that effect, and a trial in 82 people with depression found one strain, Shirota, raised beneficial bacteria and lowered bacteria linked to mental illness. Most other work was in animals or the lab, so the evidence is limited.
- Best evidence:
Limonene
Limonene is the fragrant compound that gives citrus peels their scent, and the body breaks it down into related molecules such as perillyl alcohol. Research has looked most at its anti-cancer activity, and animal studies found effects in breast, colon, liver and pancreatic cancer models, though the evidence is limited. Human data is thin: early trials tested perillyl alcohol rather than limonene, and small studies suggested heartburn symptoms eased.
- Best evidence:
Moro Orange Extract
Moro orange extract comes from a red-fleshed blood orange grown in Sicily, and it is rich in anthocyanins, plant pigments with antioxidant activity. People mostly look at it for body composition, and studies found body fat went down, though the evidence is limited. The research was small, covering 169 people in total, and muscle mass showed no clear difference, so the evidence there is very limited.
- Best evidence:
Mulberry Fruit Extract
Mulberry fruit extract is a concentrate of the dark berries of the mulberry tree, rich in anthocyanins and other plant pigments that act as antioxidants in the body. People mostly look at it for blood sugar control, and the evidence is limited: in diabetic mice and rats, the extract improved glucose control and insulin sensitivity. Nearly all of this work was in animals or cell studies, so it says little yet about how the extract affects people.
- Best evidence:
Myricetin
Myricetin is a flavonoid, a plant pigment found in foods such as berries and tea, that acts as an antioxidant in test-tube experiments. The evidence is very limited, but in lab studies it slowed the growth of several types of cancer cells and pushed bone-building cells to mature. Nearly all of this work used cells or animals, and no human trials have tested these effects, so what it does in people remains unknown.
- Best evidence:
Oleoylethanolamide
Oleoylethanolamide (OEA) is a fat-derived molecule your gut makes after a meal, where it activates a receptor called PPARα to help signal fullness and guide how the body handles fat. People mostly look at it for appetite, and the evidence is limited: animal studies consistently found less food intake, while in people, higher OEA after gastric bypass surgery was linked to metabolic improvements. No human trials have tested OEA supplements for appetite, so those findings are mostly from animals and observation rather than supplementation.
- Best evidence:
Piceatannol
Piceatannol is a polyphenol found in passion fruit seeds and grapes, closely related to resveratrol, that mops up free radicals in lab tests. People mostly look at it for insulin sensitivity, and small human studies of passion fruit seed extract found it improved in overweight people, while diabetic mice had lower blood glucose. Still, the evidence is limited, with one small study of about 50 people and mostly animal or lab work.
- Best evidence:
Spikenard
Spikenard is a fragrant Himalayan root used in traditional Ayurvedic medicine, and it seems to act on calming brain signals such as GABA. The best-supported finding is for blood pressure: in one trial of people with stage 1 hypertension, readings were lower after four weeks than with placebo, though the evidence is limited. That was a single study of 40 people, and work on anxiety, mood and memory comes mostly from animals.
- Best evidence:
Sweet Flag
Sweet flag, also called Vacha, is a wetland plant whose rhizome features in Ayurvedic medicine and is rich in a compound called β-asarone. The best-studied finding is a caution: long-term animal studies found that β-asarone caused intestinal tumors and organ damage with chronic exposure, though the evidence is limited. Reported effects on mood, seizures and immunity come from rodent and lab work, and that evidence is very limited.
- Best evidence:
Akarkara
Akarkara is the root of a daisy-like plant, Anacyclus pyrethrum, long used in traditional Ayurvedic medicine and rich in plant compounds called alkylamides. People mostly look at it for testosterone and male fertility, and in rats the root extract roughly doubled testosterone and luteinizing hormone and increased sperm-making activity. No human trials exist, so the evidence is very limited, and it's unclear whether these results carry over to people.
- Best evidence:
Bromelain
Bromelain is a mix of protein-digesting enzymes found in pineapple, and it appears to calm inflammation and swelling in tissues. People mostly look at it for acute knee pain, where the evidence is moderate, and a small study of 77 people found inflammation went down; a separate small trial found nasal congestion improved in seasonal allergies. Both findings come from small studies, so they are early signs rather than firm answers.
- Best evidence:
Celastrus Paniculatus
Celastrus paniculatus is an Indian climbing plant whose seeds have long been used traditionally, and its extracts appear to act on acetylcholine, a brain chemical involved in memory. People mostly look at it for age-related memory decline, and in rodent studies the seed extract improved memory retention. Evidence is limited, though, since nearly all of it comes from animals or lab work rather than people.
- Best evidence:
Chinese juniper
Chinese juniper is an evergreen conifer whose berries contain plant compounds, such as widdrol, that researchers study for their effects on cells. Lab studies on colon cancer cells found widdrol slowed growth and triggered cell death, and one mouse study found slower tumor growth. Nearly all of this is cell or animal work, so the evidence is very limited and says little yet about people.
- Best evidence:
Convolvulus pluricaulis
Convolvulus pluricaulis is a small creeping herb long used in Ayurvedic medicine, and its extracts appear to influence brain signaling and antioxidant defenses. People mostly look at it for memory, and rodent studies found better learning and memory, while one small human study of 30 people reported gains in auditory and visual memory. The evidence is limited, though, since most work was in animals and the human study had no placebo group.
- Best evidence:
East Indian globe thistle
East Indian globe thistle is a flowering plant used in traditional Indian medicine, whose extracts contain plant compounds that influence hormone-related enzymes and inflammation. People mostly look at it for muscle strength and testosterone, and two trials in young men found a blend with mango bark extract improved bench press, grip strength and endurance over 8 weeks. The evidence is limited, because those trials tested a blend rather than the plant alone, and most other findings come from animal or lab work.
- Best evidence:
Fisetin
Fisetin is a plant pigment found in strawberries, apples, and onions, with antioxidant and anti-inflammatory properties. Small trials found that blood markers of inflammation, IL-6 and TNF-α, went down, as did markers of senescent (aging) cells, though the evidence is limited. The studies were small, with 95 people at most, and early hints of less joint pain or lower blood glucose are very limited.
- Best evidence:
GABA
GABA is the main calming chemical messenger in the brain, where it dampens nerve activity, though little of the supplement may cross into the brain. People look at it mostly for anxiety, such as fear of flying, and the evidence is limited: studies found anxiety symptoms went down and people fell asleep sooner. Most of these studies were small, so the results are early.
- Best evidence:
Glucosamine
Glucosamine is a natural compound made from sugar and amino acids that the body uses as a building block for cartilage, the cushioning tissue in joints. Most people look at it for joint pain, especially from knee osteoarthritis, and the evidence is moderate: pain eased and overall osteoarthritis symptoms improved across a dozen studies. Even so, the studies were small, and the evidence for sudden, nonspecific knee pain was limited to one small group of 102 people.
- Best evidence:
Griffonia simplicifolia
Griffonia simplicifolia is a West African shrub whose seeds are rich in 5-HTP, which the body converts into the mood-shaping messenger serotonin. In migraine trials, about as many people improved on 5-HTP as on a standard migraine drug, mostly through milder, shorter attacks. The evidence is limited, though: the studies were small, many date from the 1980s, and most tested purified 5-HTP rather than the seed extract.
- Best evidence:
Haninjin
Haninjin is an extract of Artemisia iwayomogi, a Korean medicinal herb whose plant compounds, including coumarins and polysaccharides, appear to calm inflammatory signaling in cells. The best-studied area is allergic response, where rodent studies found the extract dampened anaphylactic reactions and allergic airway inflammation, partly by steadying mast cells that release histamine. Nearly all the work so far was in mice, rats, or cell cultures, so the evidence is very limited and says little yet about people.
- Best evidence:
Jojoba
Jojoba is a liquid wax pressed from the seeds of a desert shrub, and its structure resembles the natural oils that keep skin soft and protected. People mostly look at it for skin care, and a small trial found a jojoba-ester and glycerol formulation reduced water loss through the skin more than glycerol alone, though the evidence is very limited. Findings on inflammation, wound closure and collagen come mostly from lab or animal work.
- Best evidence:
Ku shen
Ku shen is the root of Sophora flavescens, a plant used in traditional Chinese medicine, whose alkaloids matrine and oxymatrine influence cell growth and inflammation. The evidence is very limited: lab studies found these compounds slowed cancer cell growth, and animal studies found tumors grew more slowly. Almost none of this comes from people taking it by mouth, and liver and nerve toxicity have been reported with its main alkaloids.
- Best evidence:
Longan
Longan is a tropical fruit whose pulp and seed extracts are sold as supplements, rich in polyphenols that act as antioxidants. Its best-supported finding involved bone health, where a 12-week trial in 50 older adults found lower alkaline phosphatase, a bone turnover marker, than placebo, while other markers showed no clear difference. Evidence is limited, and most other research, on memory, inflammation and blood sugar, comes from animal or lab studies.
- Best evidence:
Loquat
Loquat is a fruit tree whose leaf and seed extracts contain plant compounds, such as triterpene acids and flavonoids, that appear to influence how cells handle sugar. People mostly look at it for blood glucose, and the evidence is limited: in diabetic rodents, extracts lowered blood glucose, improved glucose tolerance and eased insulin resistance. Nearly all of this comes from animal and lab studies, so its meaning for people is unclear.
- Best evidence:
Orange Peel
Orange peel is the outer rind of the fruit, rich in flavonoids such as hesperidin that act as antioxidants and influence blood vessel function. People mostly look at it for blood pressure, and trials of hesperidin found systolic and diastolic readings came down in mildly hypertensive adults, so the evidence is moderate. Only two trials, with about 300 people, contributed, and interest in its other uses rests mostly on lab work.
- Best evidence:
Poly-γ-Glutamic Acid
Poly-γ-glutamic acid is a sticky, water-holding chain of glutamic acid made by bacteria, best known from fermented soybean natto, and it binds minerals such as calcium. Lab experiments found it scavenged free radicals and protected intestinal cells from oxidative damage, and in mice it shifted gut bacteria toward beneficial Lactobacillales, though the evidence is very limited. Nearly all of this came from cells and animals, so what it does in people remains unclear.
- Best evidence:
Rose Essential Oil
Rose essential oil is a fragrant oil steam-distilled from rose petals, and its aroma is thought to act on smell pathways linked to mood and stress. People mostly look at it for the anxiety and pain of kidney stone colic, though the evidence is limited, and small studies of its scent found blood pressure improved, breathing slowed and cortisol went down. Those studies enrolled 20 to 40 people, so they say little about colic.
- Best evidence:
Soy Lecithin
Soy lecithin is a fatty substance from soybeans, rich in phospholipids such as phosphatidylcholine, which help build cell membranes and carry fats around the body. With no single main use standing out, the best-supported finding is for high cholesterol, where a small trial found LDL cholesterol improved, though the evidence is limited. Another small study saw cortisol go down, but HDL showed no clear difference, and all of this comes from very small groups.
- Best evidence:
Sulforaphane
Sulforaphane is a compound released from broccoli and other cruciferous vegetables when they are chopped or chewed, and it switches on Nrf2, a pathway that boosts the body's own antioxidant defenses. Research found moderate evidence that it activated that pathway and raised antioxidant enzymes, and in autism studies behavior scores improved by about a third. Those autism studies were small, and the evidence for cancer-related markers such as PSA and cell growth is limited.
- Best evidence:
Tetraselmis Chuii
Tetraselmis chuii is a marine microalga, a tiny single-celled plant of the sea, that makes antioxidant compounds and is sold as a whole-food supplement. People mostly look at it for exercise recovery, and three small trials found less muscle damage after hard exercise, less drop in jump power, and better perceived recovery. Still, the evidence is limited: those trials were short and had only 19 to 32 people each.
- Best evidence:
Theacrine
Theacrine is a plant compound related to caffeine, found in a bitter Chinese tea called kucha, and it appears to act on the brain's energy and alertness pathways. People mostly look at it for energy and fatigue, and trials found a moderate rise in perceived energy and a moderate drop in tiredness, though the evidence is only limited. Most studies were fairly small, and it did not change blood pressure or heart rate the way caffeine does.
- Best evidence:
Thunder god vine
Thunder god vine is a plant used in traditional Chinese medicine, and its extracts contain compounds such as triptolide and celastrol that dial down the activity of the immune system. People mostly look at it for rheumatoid arthritis, where human studies found disease activity fell, and the evidence is moderate. That same immune-dampening effect comes with serious side-effect risks, and most other research so far has been lab or animal work.
- Best evidence:
Toothache plant
Toothache plant is a flowering herb whose blooms contain spilanthol, a compound that numbs the mouth and calms irritated tissue. No main use stands out, but the best-supported human findings involve erectile function, where three trials of one branded extract found improved scores over one to three months, and testosterone rose in men with erectile dysfunction. The evidence is limited, since all the human work came from a single research group, and most of the wider research on pain and inflammation was in animals or cells.
- Best evidence:
Triphala (Emblica officinalis, Terminalia chebula, Terminalia bellirica)
Triphala is a traditional Ayurvedic blend of three fruits, amla and two myrobalans, whose plant compounds have a gentle laxative effect and support the gut. People mostly look at it for constipation-predominant irritable bowel syndrome, and the evidence for that use is limited. Trials in constipation more broadly found bowel movements became more frequent within a couple of weeks, but those studies were short, so they say little about long-term use.
- Best evidence:
Urolithin A
Urolithin A is a compound gut bacteria make from foods like pomegranates and walnuts, and it helps cells clear out worn-out mitochondria, the parts that produce their energy. People mostly look at it for healthy muscle aging, where the evidence is moderate: trials found muscle strength improved by about 12% and muscles managed more contractions before tiring. Gains in walking distance were not statistically significant, and the aerobic findings came from small studies, so that evidence is limited.
- Best evidence:
Valine
Valine is an essential amino acid, so the body must get it from food, and it helps build muscle protein. Most interest centers on muscle, and a small human study found that a mix of branched-chain amino acids including valine slowed protein loss during bed rest. Still, the evidence is very limited, and the benefit was credited to the mixture, not valine alone.
- Best evidence:
Zeaxanthin
Zeaxanthin is a yellow plant pigment that gathers in the macula, the center of the retina, where it helps filter blue light. People often look at it for nearsightedness progression, though the evidence there is limited, drawn from about 350 participants. Better-supported findings concern the macula itself: trials found macular pigment rose, and a large trial found lutein and zeaxanthin together reduced age-related macular degeneration progression.
- Best evidence:
Akkermansia muciniphila
Akkermansia muciniphila is a bacterium that lives in the gut's mucus lining, where it helps support the gut barrier and metabolism. In a trial of 90 people, a pasteurized form improved insulin sensitivity by about 29% over placebo, and a smaller study found lower insulin levels in metabolic syndrome. The evidence is limited, though: studies were small, and blood sugar and weight benefits appeared only in some people.
- Best evidence:
Arnica
Arnica is a yellow mountain flower whose extracts are thought to calm inflammation. Most people look at it for recovery after surgery, where the evidence is moderate: small trials found less swelling after knee ligament surgery and smaller bruise areas, though a pooled analysis found only a small effect that just missed statistical significance. Other placebo-controlled trials found no difference in pain or bruising, so the picture is mixed.
- Best evidence:
Bitter Melon
Bitter melon is a gourd whose fruit and extracts contain plant compounds that may influence how the body handles sugar. People mostly look at it for blood sugar in diabetes, but pooled trials found no significant change in fasting glucose or HbA1c, and the evidence is limited. One small 12-week prediabetes trial found better after-meal glucose, while low blood sugar has been reported, including in children.
- Best evidence:
Cistanche (Cistanche tubulosa/deserticola)
Cistanche is a desert plant whose fleshy stem has long been used in traditional Chinese medicine, and it contains compounds with antioxidant and nerve-protecting properties. With no single main use, the best-supported finding comes from an eight-week trial in 48 men doing resistance training, where testosterone and strength rose and cortisol and muscle-damage markers fell. That was one small trial, and effects were stronger in people already trained. Evidence for fatigue and Alzheimer's is less settled, and much of the brain work comes from animals.
- Best evidence:
Citrus Bergamot (Bergamot Polyphenolic Fraction)
Bergamot polyphenolic fraction is a flavonoid-rich extract of a citrus fruit whose compounds resemble part of a statin and may slow the liver enzyme that makes cholesterol. People mostly look at it for high cholesterol, and the evidence is strong: a systematic review found LDL cholesterol fell in most studies, and bergamot ranked best among plant compounds compared. Trials lasted only weeks to months, and the evidence is weaker for blood sugar and artery health.
- Best evidence:
Coluracetam
Coluracetam is a lab-developed compound that boosts how nerve cells take up choline, the raw material for acetylcholine, a chemical messenger involved in learning and memory. In rodents with impaired cholinergic function, it preserved and increased choline uptake and improved maze learning and working memory. The evidence is very limited, though: it is mostly animal work, and company trials in Alzheimer's disease and depression with anxiety did not show benefit.
- Best evidence:
Dendrobium
Dendrobium is a genus of orchids whose stems have long been used in traditional Chinese medicine, and they contain polysaccharides and bibenzyl compounds that are thought to give them their activity. People mostly look at it for digestive support, and the evidence is limited: animal studies found it protected the stomach lining by boosting mucus secretion. No controlled human trials have looked at stomach outcomes, so what works in animals remains unproven in people.
- Best evidence:
Diosmin
Diosmin is a citrus-derived flavonoid that helps veins keep their tone and may calm inflammation and leakage in small vessels. People mostly look at it for vein problems, and the evidence is strongest for chronic venous insufficiency, where trials found less leg swelling and eased pain, heaviness and fatigue. Much of that work tested flavonoid blends containing diosmin, and a large review found little difference in quality of life.
- Best evidence:
European Raspberry
European raspberry is a red berry rich in plant compounds like anthocyanins, which work as antioxidants. People look at it for metabolic health, yet the evidence is very limited: a review found no clear difference in blood glucose or C-reactive protein. That rested on one small study of nine people, so it says little about larger or different groups.
- Best evidence:
Guggul
Guggul is a resin from the mukul myrrh tree, long used in Ayurvedic medicine, and its guggulsterones are thought to influence how the body handles fats. People often look at it for high cholesterol, yet in small studies of 137 people, cholesterol readings got worse: LDL went up and HDL went down. The evidence is limited, so these findings are tentative and need larger studies.
- Best evidence:
Higenamine
Higenamine is a plant compound that switches on beta-adrenergic receptors, the same docking points adrenaline uses to speed and strengthen the heart. Lab and animal studies found it increased the force of heart muscle contractions, and in isolated mouse heart tissue it raised the heart rate too. The evidence is very limited, though: nearly all of it comes from guinea pigs, mice and cultured cells, with little human research to confirm it.
- Best evidence:
Horse Chestnut
Horse chestnut is a tree whose seed extract contains aescin, a compound thought to firm up vein walls and limit fluid leaking from tiny blood vessels. People mostly look at it for chronic venous insufficiency, when leg veins struggle to send blood back up, and the evidence is strong: a trial of 297 people found signs of the condition improved. Not every measure moved, though, since HDL cholesterol showed no clear difference in a very small study of 40 people.
- Best evidence:
Huperzine A
Huperzine A is a compound extracted from a Chinese club moss that slows the breakdown of acetylcholine, a brain chemical involved in memory and learning. People mostly look at it for Alzheimer's disease, where the evidence is moderate: a meta-analysis found thinking-test scores improved at 8, 12, and 16 weeks, and memory scores improved too. The studies only lasted a few months, and evidence for daily activities and vascular dementia is limited.
- Best evidence:
Hydroxyapatite
Hydroxyapatite is the calcium-phosphate mineral that makes bones and teeth hard. Trials found a form paired with collagen kept bone density steadier than calcium carbonate did, and cavity rates with hydroxyapatite toothpaste were similar to those with fluoride toothpaste. The evidence is moderate for both, but it is limited for enamel repair and tooth sensitivity, where much of the work came from lab studies.
- Best evidence:
Lion's Mane
Lion's mane is a shaggy, edible mushroom whose compounds are thought to support the growth and upkeep of nerve cells. People look at it mainly for anxiety during menopause, and a small study of 30 people found anxiety symptoms eased, though the evidence is limited. A pilot in 41 people with early Alzheimer's found no clear difference in symptoms, so it is early days.
- Best evidence:
Lutein
Lutein is a yellow-orange carotenoid that gathers in the macula at the back of the eye, where it helps filter light and supports retinal health. People mostly look at it for nearsightedness progression, though the evidence for that use is limited. Research in 117 people with obesity found no clear difference in blood pressure or apolipoprotein B, and that evidence is very limited too.
- Best evidence:
Luteolin
Luteolin is a plant flavonoid, found in foods like celery and peppers, that works as an antioxidant and calms inflammatory signaling in cells. Evidence is moderate for smell recovery after COVID, where a review of five studies found a luteolin and PEA combination plus smell training worked better than training alone. That product combined two ingredients, and most other findings come from animal or lab work.
- Best evidence:
Magnolia Bark (Magnolia officinalis)
Magnolia bark comes from the Magnolia officinalis tree, and its compounds honokiol and magnolol appear to calm brain signaling through GABA receptors. People look at it for stress, and in a four-week trial, a magnolia and phellodendron blend lowered cortisol and improved mood scores versus placebo, so the evidence is moderate. That trial was small and used a combination product, and the anxiety and sleep findings rest mostly on animal and lab work.
- Best evidence:
Mitoquinone mesylate
Mitoquinone mesylate, or MitoQ, is a form of coenzyme Q10 built to gather inside mitochondria, the cell's energy factories, where it acts as an antioxidant. Small trials found oxidative stress markers went down, including oxidized LDL in older adults, but the evidence is limited. Most studies were small, and a year-long trial in people with early Parkinson's disease found no difference from placebo.
- Best evidence:
Muira puama
Muira puama is an Amazonian shrub whose bark and roots yield extracts that appear to nudge brain chemistry, including acetylcholine breakdown and certain serotonin receptors. In studies of memory and thinking, the extract improved memory retrieval in young and aged mice, but the evidence is limited. No human cognitive trials exist, so it is unknown whether this carries over to people.
- Best evidence:
Multivitamin
A multivitamin combines many vitamins and minerals in one product, helping cover nutrients the body needs for energy, immunity, and tissue repair. People most often look at it for nutritional support in HIV, where the evidence is strong, since deficiencies are common there. In well-nourished adults, large studies found it did not lower cardiovascular events or cancer rates, or slow cognitive decline.
- Best evidence:
Nonnutritive Sweeteners
Nonnutritive sweeteners are compounds, such as aspartame, sucralose and stevia extracts, that taste sweet but add almost no calories, so they stand in for sugar in drinks and foods. People mostly look at them for weight control, and reviews of randomized trials found body weight went down and people ate less food, with moderate evidence for both. The effects were small, though, and each finding came from a single review; the evidence for HDL cholesterol was very limited, with no clear difference.
- Best evidence:
Oxaloacetate
Oxaloacetate is a molecule your cells make as part of the cycle that turns food into usable energy. People mostly look at it for brain protection, and the evidence is limited: in mouse studies it boosted the growth of new mitochondria, reduced inflammation and stimulated new nerve cells, while lab work found neurons handled energy better. Almost all of this comes from animal or cell experiments, so what it means for people remains unclear.
- Best evidence:
Panax notoginseng
Panax notoginseng is a root used in traditional Chinese medicine, and its saponins are thought to influence blood clotting and inflammation. People most often look at it for recovery after an ischemic stroke, and the evidence is moderate: trials found that adding its saponins to standard care improved neurological function and everyday activities. The large trial was run in China, and ideas about reduced brain inflammation come mostly from animal work.
- Best evidence:
Pelargonidin
Pelargonidin is a red-orange pigment in strawberries and other berries that acts as an antioxidant in the body. People mostly look at it for Alzheimer's disease, and a study of 575 people who had died linked higher intake to less amyloid-beta buildup and fewer tau tangles, though the evidence is limited. That was an observational link, clearest in people without the APOE e4 gene, and most other research is animal or lab work.
- Best evidence:
Phellodendron amurense
Phellodendron amurense is the Amur cork tree, whose bark is used in traditional herbal medicine and contains plant compounds that influence inflammation. People mostly look at it for joint health, and in a small eight-week pilot trial, osteoarthritis symptoms eased with a Phellodendron and citrus combination, though the evidence is limited. Other support comes mostly from animal or lab studies.
- Best evidence:
Phosphorus
Phosphorus is a mineral that pairs with calcium to build bones and teeth and helps cells store energy. People look at it mainly for supportive care in acute liver failure, where blood phosphorus often runs low as the liver regenerates, and the evidence is moderate. Most other research looked at too much rather than too little, and human studies found high intake raised parathyroid hormone, including in kidney disease.
- Best evidence:
Pueraria Mirifica
Pueraria mirifica is a plant from Thailand whose root contains phytoestrogens, plant compounds that can act on the body's estrogen receptors. With no single main use established, the best-supported finding involves cholesterol: in postmenopausal women, HDL, the "good" cholesterol, and apolipoprotein B both improved, though the evidence is limited. That work came from one small study of 17 women, so it says little about other groups and needs larger trials to confirm.
- Best evidence:
Punicalagins
Punicalagins are large antioxidant compounds found in pomegranate peel and juice, which gut bacteria break down into smaller molecules the body can absorb. People mostly look at them for prostate cancer, but the evidence is limited: in one small study of 46 people, nitric oxide went up, while estrogen showed no clear difference. That is a very thin base, so these findings say little about whether punicalagins change anything that matters for prostate health.
- Best evidence:
Sacred lotus
Sacred lotus is an aquatic plant whose leaves, seeds and roots are used in foods and herbal teas, and it is rich in polyphenols and alkaloids like nuciferine. The evidence is very limited, but in diabetic rodents leaf extracts lowered blood glucose and improved insulin sensitivity, and in other animal models they lowered total cholesterol and triglycerides. No human trials have tested this, so results may not carry over to people.
- Best evidence:
Safed Musli
Safed musli is a root used in traditional Indian herbal medicine, rich in saponins and polysaccharides. People mostly look at it for sexual function and libido, and the evidence is limited: multiple rodent studies consistently found dose-dependent aphrodisiac effects, including more mating behavior. Human data is scarce and muddied because trials used combination formulas and had industry funding, so effects of safed musli alone remain unclear.
- Best evidence:
Shivlingi
Shivlingi is the seed of a climbing plant, Bryonia laciniosa, used in traditional Indian herbal medicine and containing plant compounds such as saponins. People mostly look at it for male reproductive health, and the evidence is very limited: in rats, testosterone, sperm count and mating behavior all rose. Every finding came from animal or lab studies, and no human trials exist, so it is unclear whether any of this applies to people.
- Best evidence:
Society garlic
Society garlic is a South African plant whose leaves and roots are used as a garlic-like herbal remedy, and its sulfur-rich compounds are thought to be what gives it biological activity. People mostly look at it for blood pressure, and in a 7-week study, rats bred to be salt-sensitive had lower systolic blood pressure after a root extract. That evidence is very limited, though: it comes almost entirely from animal and lab work, and no human trials have been reviewed here.
- Best evidence:
Strontium
Strontium is a mineral that behaves like calcium and settles into bone, where it may support bone building and slow breakdown. People look at it for low bone density, and trials of prescription strontium ranelate found density rose and spinal fractures became about 40% less common in postmenopausal women, with strong evidence for fractures. That form was restricted in Europe in 2014 over heart and clot concerns, and over-the-counter citrate has not been tested for fractures.
- Best evidence:
Sulbutiamine
Sulbutiamine is a lab-made compound built from two thiamine (vitamin B1) molecules, a form that dissolves in fat and reaches the brain more easily than plain thiamine. The little research so far looked at people with type 2 diabetes, and the evidence is very limited: blood glucose and nerve-related symptoms showed no clear difference. That comes from one small open trial of 30 people, so it says little beyond that group.
- Best evidence:
Systemic Enzymes (Bromelain/Trypsin/Rutin)
Systemic enzymes combine bromelain from pineapple, the digestive enzyme trypsin, and the plant compound rutin, and people use them for their effects on inflammation and swelling. Most look at them for knee osteoarthritis, where the evidence is strong: a pooled analysis of six trials found pain and joint function improved about as much as with the anti-inflammatory drug diclofenac. Evidence for sports injuries and swelling after surgery is only moderate, and the knee findings come from this specific combination.
- Best evidence:
Tea Catechins
Tea catechins are antioxidant plant compounds found in green tea and other teas, and they influence how the body handles fat and sugar and how cells cope with oxidative stress. People mostly look at them for fat burning, and the evidence is moderate: studies found fat oxidation increased both during exercise and at rest. The evidence for weight loss is limited, with small gains of about 1 to 2 kg over 12 weeks, mostly in Asian populations and alongside caffeine.
- Best evidence:
Trichopus zeylanicus
Trichopus zeylanicus is a forest plant from southern India, known as the ginseng of Kerala, whose extracts contain polyphenols and other compounds that act as antioxidants. People mostly look at it for fatigue, and rodent studies found extracts lengthened swimming time in young rats and aged mice without stimulant-like effects. The evidence is limited, though, because nearly all of this work was in animals or the lab, so it says little yet about people.
- Best evidence:
Tryptophan
Tryptophan is an essential amino acid found in protein foods, which the body uses to build proteins and to make serotonin and melatonin. People mostly look at it for sleep, and the evidence is moderate: trials found people fell asleep sooner, especially those with mild insomnia, and they also rated themselves sleepier. For mood the evidence is limited, with better results than placebo in mild-to-moderate depression but no benefit in severe depression.
- Best evidence:
Uva ursi
Uva ursi, or bearberry, is a shrub whose leaves contain arbutin, which the body turns into the antimicrobial compound hydroquinone. People mostly look at it for bladder infections, and in one small trial of women with recurrent cystitis, none taking it had a recurrence over a year, versus 23% on placebo. The evidence is limited, though, and much of the other research is lab or animal work.
- Best evidence:
Violet Flower
Violet flower is the blossom of sweet violet, a plant used in traditional herbal remedies and rich in anthocyanin pigments and coumarin compounds with antioxidant and anti-inflammatory properties. People mostly look at it for cough, and in a double-blind trial of 182 children with asthma, coughing eased faster with violet syrup than with placebo alongside usual asthma medicine. Still, the evidence is limited, and other studies were small or lab-based.
- Best evidence:
White Kidney Bean Extract
White kidney bean extract is a concentrate from white beans that blocks alpha-amylase, an enzyme your gut uses to break starch into sugars. People mostly look at it for weight loss, and the evidence is moderate: meta-analyses of trials found modest drops in body weight and larger, more consistent drops in body fat. Most studies were small and fairly short, and the average weight change was only a kilogram or two, so the effect is real but modest.
- Best evidence:
Bromantane
Bromantane is a synthetic compound developed in Russia that appears to raise the brain's dopamine-making machinery, based on rat studies. People mostly look at it for asthenia, the exhaustion and weakness seen in neurasthenia, and the evidence is moderate: several trials, including a placebo-controlled one, found symptoms eased. Most other claims, such as for anxiety or physical performance, rest largely on animal work, and the human studies were fairly small and short.
- Best evidence:
Andrographis
Andrographis is a bitter herb from South and Southeast Asia whose compounds appear to calm inflammation and stimulate immune activity. Most people look at it for acute respiratory infections such as colds, and a large meta-analysis found symptoms improved versus placebo, usual care and other herbal therapies, with cough and sore throat easing too. Those cough and sore throat trials were fairly small, though, and the evidence for flu is limited.
- Best evidence:
Artemisia annua
Artemisia annua, or sweet wormwood, is a plant whose leaves contain artemisinin, a compound that damages malaria parasites in the blood. Artemisinin-based combination drugs became the WHO-recommended first-line option for malaria, and large studies found they cleared the infection in over 95% of uncomplicated cases. That strong evidence is for those combination medicines; work on arthritis and hay fever symptoms was small, and the evidence there is limited.
- Best evidence:
Asafoetida
Asafoetida is a pungent, sulfur-rich resin from the roots of Ferula plants, used in cooking and traditional remedies. The evidence is limited, but in small trials symptoms improved: a Ferula capsule did better than metronidazole on clinical symptoms, and in a placebo-controlled trial most people reported better overall symptoms and quality of life. Those studies involved only 43 to 70 people, and for irritable bowel syndrome the evidence is very limited.
- Best evidence:
Bakuchi
Bakuchi is the seed of Psoralea corylifolia, a plant from traditional medicine that yields bakuchiol, a compound used in skin care as a plant-based alternative to retinol. For skin health the evidence is moderate: in a 12-week trial, wrinkles and pigmentation both improved about as much as with retinol, with less scaling and stinging. That trial included only 44 people, and vitiligo and psoriasis research is very limited, with psoriasis tested only in mice.
- Best evidence:
Beta-Carotene
Beta-carotene is the orange plant pigment in carrots and sweet potatoes, which the body can turn into vitamin A and which also works as an antioxidant. People mostly look at it for sun sensitivity such as polymorphous light eruption, where the evidence is moderate and studies found mixed but partly positive results. Large trials found no drop in melanoma or other skin cancers, and in smokers it was linked to higher lung cancer risk.
- Best evidence:
Black Barberry Extract
Black barberry is a shrub whose berries and roots contain berberine, a plant compound that influences how cells handle sugar and fat. Pooled trials found lower fasting blood sugar and HbA1c in people with type 2 diabetes, along with reduced total cholesterol, LDL cholesterol and triglycerides, and the evidence is moderate for each. Weight loss was modest, about 1.5 kilograms, and the evidence there is limited.
- Best evidence:
Black Garlic Extract
Black garlic extract comes from garlic aged slowly under heat and humidity until it darkens, a process that creates antioxidant compounds. Pooled analyses found moderate evidence that LDL and total cholesterol were reduced and that systolic blood pressure fell by roughly 2.5 to 5 points overall. Those effects were modest, some of the data covers garlic more broadly, and the evidence for blood sugar is only limited.
- Best evidence:
Butterfly Pea
Butterfly pea is a blue-flowered climbing plant, used in traditional medicine and as a natural food dye, whose petals contain ternatins, pigments that act as antioxidants. People mostly look at it for memory, and the evidence is limited: in rodents, root extract improved memory and learning in maze tests, sometimes similar to piracetam or Bacopa, possibly by raising acetylcholine. Those results come from animal work, so it remains unclear whether the same happens in people.
- Best evidence:
Calcium-D-Glucarate
Calcium-D-glucarate is the calcium salt of glucaric acid, a compound found in fruits and vegetables that may block beta-glucuronidase, an enzyme involved in how the body clears hormones and other substances. People mostly look at it for cancer prevention, but the evidence is very limited: in rodents, it lowered tumor rates across several cancer types. No human trials have tested this, and the rodent doses were far higher than any supplement, so the findings say little about people yet.
- Best evidence:
Capsicum Carotenoids
Capsicum carotenoids are the red pigments in peppers and paprika, mainly capsanthin and capsorubin, which act as antioxidants inside the plant. The best-studied finding is on antioxidant activity, where the evidence is very limited: in chemical tests, both pigments mopped up damaging free radicals and held up better than beta-carotene. Nearly all of this comes from lab and cell work, so how it translates to people is unknown.
- Best evidence:
Cat's whiskers
Cat's whiskers is a Southeast Asian herb, also called Orthosiphon stamineus, whose leaves are traditionally brewed as a tea and used for urinary health. People mostly look at it for increased urine flow, but the evidence is very limited: one study of 80 people found no clear difference in diuresis. That study tested it within a mix of four herbal remedies, so it says little about cat's whiskers on its own.
- Best evidence:
Chaihu Longgu Muli Decoction
Chaihu Longgu Muli Decoction is a traditional East Asian herbal formula that, in rodent studies, helped keep the body's stress-hormone feedback working normally. People mostly look at it for depression, and meta-analyses found scores fell more with it, alone or added to SSRIs, than with antidepressants alone, including after a stroke, and the evidence is moderate. Evidence for anxiety and blood pressure is only limited, and the stress findings are mostly from animals.
- Best evidence:
Chinese Hawthorn
Chinese hawthorn is the tart red fruit of a shrub long eaten and used in traditional Chinese medicine, and it contains flavonoids and procyanidins that act as antioxidants in the body. People look at it mainly for cardiovascular health, and in mouse and rat studies the extract consistently lowered total cholesterol, LDL and triglycerides, so the evidence is limited. No controlled human trials were found, so it remains unclear whether the same effects would appear in people.
- Best evidence:
Clary sage
Clary sage is an aromatic herb whose essential oil is used in aromatherapy, and its scented compounds are thought to act on the nervous system to promote relaxation. People mostly look at it for urinary incontinence, and the evidence there is limited: in one small trial of women having a bladder examination, blood pressure improved after inhaling it. That study was small, with 34 women, and it measured blood pressure rather than bladder symptoms, so it says little about incontinence itself.
- Best evidence:
Clubmoss
Clubmoss is a group of moss-like plants, including Huperzia serrata, whose alkaloid huperzine A slows the enzyme that breaks down acetylcholine, a brain messenger for memory. People mostly look at it for thinking skills in Alzheimer's disease, and trials of huperzine A found cognitive benefits, though the evidence is limited. Those trials used purified huperzine A rather than whole clubmoss, and most research on the herb itself was in animals or labs.
- Best evidence:
Cnidium monnieri
Cnidium monnieri is a plant long used in traditional Chinese medicine, and its fruit contains osthole, a compound that acts on the nitric oxide pathway that helps smooth muscle relax. People mostly look at it for erectile function, where the evidence is limited: lab work found osthole blocked PDE5 in penile tissue, and animal studies found better erectile response, though weaker than sildenafil. No human trials exist, so its effect in people is unknown.
- Best evidence:
Cucurbita pepo
Cucurbita pepo is the pumpkin plant, whose seed oil and extract are used as a supplement thought to act on prostate and bladder tissue. People mostly look at it for benign prostate enlargement, and the evidence is moderate: several small trials, including one 12-month placebo-controlled study, found urinary symptoms eased in men. Sample sizes were modest, and findings for overactive bladder and hair growth are much thinner.
- Best evidence:
DIM
DIM (diindolylmethane) forms when the body digests broccoli-family vegetables, and it influences how estrogen is processed. People look at it for HPV support and hormone balance, and the evidence is limited: studies found it raised a urinary estrogen ratio in a favorable direction and changed several estrogen metabolites. Those are hormone markers, not clinical outcomes, and in breast cancer patients, very limited research found lower tamoxifen metabolites, which may reduce its effectiveness.
- Best evidence:
Ecklonia Cava
Ecklonia cava is a brown seaweed that grows off the coasts of Japan and Korea, and it is rich in polyphenols called phlorotannins that act as antioxidants in the body. People mostly look at it in the context of being overweight, and a small set of trials in 97 people found blood glucose and blood pressure both improved, though the evidence is limited. Those studies were small, so it is too early to say how well the results would hold up in other groups.
- Best evidence:
Essential amino acid (EAA)
Essential amino acids are the nine protein building blocks your body cannot make, so they must come from food. Most people look at them for muscle, and human trials using tracer methods consistently found that they boosted muscle protein synthesis in the short term, with moderate evidence. Findings for lean mass and strength in older adults were mixed and limited, so that short-term boost has not clearly become bigger muscles.
- Best evidence:
Evodia rutaecarpa
Evodia rutaecarpa is a fruit used in traditional Chinese medicine, and its main compound, evodiamine, activates the same heat-sensing receptor as chili peppers. In lab studies, evodiamine slowed the growth of colon and kidney cancer cells and pushed them toward self-destruction, but the evidence is very limited. No human cancer trials exist, and a rat study found evodiamine is poorly absorbed by mouth.
- Best evidence:
Flavanols
Flavanols are plant compounds in cocoa, tea, and apples that help blood vessels relax by raising nitric oxide. People mostly look at them for heart health, and a large trial of over 21,000 people found cocoa flavanols reduced cardiovascular deaths, while other work found better blood vessel function. Still, the evidence is limited: the death finding rests on one trial, and the blood pressure work was mostly lab-based.
- Best evidence:
Flavonols
Flavonols are plant compounds found in onions, kale, tea and berries that act as antioxidants in the body. People mostly look at them for brain health, and the evidence is limited: in one large study of older adults, those eating the most flavonols had roughly half the risk of Alzheimer's dementia. That study only observed diets, and most other findings come from lab work.
- Best evidence:
Fructose
Fructose is a simple sugar found in fruit, honey, and table sugar, and the liver does most of the work of breaking it down. Trials found that high intake raised blood triglycerides, especially when people ate extra calories, and liver fat and uric acid rose too. Still, the evidence is limited, and swapping it for other carbs at the same calories did not cause weight gain.
- Best evidence:
Gelatin
Gelatin is a protein made by cooking collagen from animal skin and bones, and it supplies amino acids like glycine that the body uses to build connective tissue. Research has looked mostly at joints and skin, and studies found a modest reduction in joint pain, especially in osteoarthritis, along with slightly better skin elasticity and hydration. The evidence is limited, though, since the studies were small.
- Best evidence:
Glycine
Glycine is the simplest amino acid, a building block for proteins like collagen that also acts as a calming messenger in the brain and helps nerve cells respond to other signals. Most research on it centers on schizophrenia, where three small studies with about 50 people found symptoms improved when it was added to usual medication, and the evidence is moderate. Cognition also improved in one very small group of 17 people, but that evidence is limited, so these results are early and mostly apply to people already on antipsychotic medicines.
- Best evidence:
Gou-teng
Gou-teng is the hooked stem of a climbing plant used in traditional Chinese medicine, and its alkaloids act on serotonin receptors, calcium channels and nerve-signaling pathways in the brain. Little research on it has been reviewed here so far, and what exists mostly points to protection of nerve cells in animal and lab work. No trials of Gou-teng on its own have tested it in people, so the evidence is limited at best.
- Best evidence:
Hyaluronic Acid
Hyaluronic acid is a gel-like sugar molecule found naturally in skin, joints, and eyes, where it holds large amounts of water and keeps tissues lubricated. Most people look at it for dry eye, and a pooled analysis of eye drops found dry eye symptoms improved, with moderate evidence behind that result. The effect was small, though, and it came from a single analysis of 582 people, so it speaks to eye drops rather than to capsules or pills.
- Best evidence:
L-Cysteine
L-cysteine is an amino acid the body uses to build proteins such as keratin and to make glutathione, one of its main internal antioxidants. People mostly look at it for antioxidant status, and a few small human studies found it protected against oxidative stress from hard exercise, including less DNA oxidation and better-preserved red blood cell enzyme activity. Still, the evidence is limited, since only about 60 people took part in total, and the alcohol and hair findings come mostly from animal work.
- Best evidence:
L-Threonate
L-threonate is a natural breakdown product of vitamin C, often sold paired with minerals such as calcium or magnesium. The most notable finding came from a 2026 study in obese mice, where it worked alongside intermittent fasting to lower body weight and food intake, though the evidence is very limited. No human trials of this exist, and other work, on hair, bone and vitamin C uptake, was done in cells in lab dishes.
- Best evidence:
Lactosucrose
Lactosucrose is a sugar made from lactose and sucrose that resists digestion in the small intestine and serves as food for bacteria in the colon. People mainly look at it for gut bacteria, and the evidence is limited: people with inflammatory bowel disease had more Bifidobacterium after two weeks, and young women's stool acidity and fatty acid profiles shifted in a healthy direction. Most of the work was in animals, and the human studies were tiny.
- Best evidence:
Luo Bu Ma
Luo Bu Ma is a plant from traditional Chinese herbal medicine, and its flavonoid-rich leaf extract is studied for effects on the nervous system and blood vessels. In trials of one standardized extract, people's sleep improved: they fell asleep and stayed asleep more easily in a small study, and sleep disturbance scores were better over six weeks in a larger trial. The evidence is limited, though: just two human trials, both using the same product.
- Best evidence:
Lycopene
Lycopene is the red pigment in tomatoes and a carotenoid antioxidant that the body stores in tissues such as the prostate and skin. Most people look at it for urinary symptoms tied to the prostate, and the evidence for that use is limited. Studies on its other uses, from skin and sperm to blood vessels, were mostly small, and blood-vessel function improved in people with heart disease but not in healthy volunteers.
- Best evidence:
Matured Hop Extract
Matured hop extract is a concentrate of bitter acids formed as hops age, and animal work suggests it may act on the brain through the vagus nerve. In small trials, people reported less fatigue and anxiety than on placebo, and older adults did better on attention and verbal fluency tests. The evidence is limited, though, since the human studies were small and much of the mechanism work came from animals.
- Best evidence:
Menthol
Menthol is the cooling compound in peppermint, which activates cold-sensing nerve receptors and can relax smooth muscle. The evidence is strongest for digestive discomfort: across roughly 800 participants, peppermint oil, with menthol as its key active ingredient, eased irritable bowel symptoms including abdominal pain and spasms, and the evidence is moderate. Other uses, such as short-term muscle pain relief, tension headache, and feeling cooler while exercising in heat, have limited evidence from small to moderate studies.
- Best evidence:
Nefiracetam
Nefiracetam is a lab-made member of the racetam family, thought to influence how brain cells signal to one another. Research has focused on apathy in people with depression after a stroke, and a double-blind trial of 137 people found apathy improved, though the evidence is limited. That same trial saw no clear difference in depression symptoms, and as a single small study, it leaves much unanswered.
- Best evidence:
New Zealand Pine Bark Extract
New Zealand pine bark extract, sold as Enzogenol, is a concentrated source of plant compounds called flavonoids from the bark of Pinus radiata trees, which act as antioxidants in the body. Its best-supported finding is for blood glucose, though the evidence is limited: in a small crossover trial of 25 healthy people, blood sugar peaked lower after a meal. Most of the other work was in diabetic mice, and the few human findings on blood pressure and blood flow came from one small pilot without a placebo group.
- Best evidence:
Paederia foetida
Paederia foetida is a climbing vine used in traditional Ayurvedic medicine, and its extracts contain bioactive compounds that are not well characterized. The clearest finding involves male hormones: in a rat study, its extract raised testosterone levels, and a rodent study reported aphrodisiac effects, though the evidence is very limited. All of this comes from animals or lab work, with no human trials, so it says little about what people might experience.
- Best evidence:
Persicaria Minor
Persicaria minor is a leafy, aromatic herb from Southeast Asia, also called kesum, whose extracts are rich in plant compounds with antioxidant activity. People mainly look at it for memory and thinking in older age, and the evidence there is limited: one small six-month trial in older adults with mild cognitive impairment found better visual memory, while rodent studies also showed better memory. That trial had only 30 people, and the other findings, such as mood and antioxidant effects, come from single small studies or lab work.
- Best evidence:
Pinitol
Pinitol is a compound found in soybeans and some other plants, and the body converts it into a form of inositol that appears to help cells respond to insulin. People mostly look at it for blood sugar, and small trials in people with type 2 diabetes found lower after-meal glucose, fasting glucose and HbA1c, especially in those whose control was poorer. The evidence is limited, though: the trials were small, one found no clear benefit, and much of the wider research comes from animal or lab work.
- Best evidence:
Potassium
Potassium is a mineral and electrolyte that helps nerves, muscles, and the heart work, and it balances sodium and fluid inside and outside cells. Most people look at it for high blood pressure, and two meta-analyses of randomized trials, covering about 1,800 people, found blood pressure improved, with moderate evidence. Those results mostly apply to people who already had hypertension, and one smaller analysis found no clear difference in bone density.
- Best evidence:
Pramiracetam
Pramiracetam is a lab-made compound from the racetam family, thought to influence acetylcholine, a brain messenger involved in memory. People mostly look at it for memory, and the evidence is limited: two small studies found memory improved. Those studies included just 35 people in total, and one involved young men with memory problems after head injury, so the results say little about healthy adults.
- Best evidence:
Purple Nutsedge
Purple nutsedge is a tuber-producing plant, also called Cyperus rotundus, long used in Ayurvedic tradition for digestive and menstrual complaints. Its extracts contain sesquiterpenes and phenolic compounds. With no main use established, the best-supported finding is that rodent studies consistently found reduced inflammation, though the evidence is limited. Everything so far comes from animal and lab work, and no human trials have tested it.
- Best evidence:
Red Spinach Extract
Red spinach extract is a nitrate-rich plant extract that the body can turn into nitric oxide, a molecule that helps blood vessels widen. People mostly look at it for aerobic exercise performance, and the evidence is limited: in small crossover trials, people finished a 4-km cycling time trial faster than on placebo. Only 42 people took part across those studies, so the findings are early.
- Best evidence:
Rhamnogalacturonan I
Rhamnogalacturonan I is a branched plant fiber found in carrots and citrus that appears to interact with immune cells. In one trial, healthy volunteers exposed to a cold virus had milder cold symptoms and better quality of life after carrot-derived RG-I than after placebo, and their natural killer cell activity went up. The evidence is limited to that single trial, and other immune findings come mostly from animal or lab studies.
- Best evidence:
Rutin
Rutin is a plant bioflavonoid that helps strengthen the walls of tiny blood vessels and makes them less fragile. People mostly look at it for spider veins, though the evidence for that use is limited. In small studies on chronic venous insufficiency, people had modest relief from leg heaviness, cramps and ankle swelling, but it did not make bulging varicose veins disappear.
- Best evidence:
Salacia Reticulata
Salacia reticulata is a woody vine from South Asia whose root and stem contain compounds that slow carbohydrate digestion in the gut. People mostly look at it for blood sugar, and studies found blood glucose improved, with moderate evidence, while HbA1c also improved in one small trial in type 2 diabetes. Still, the HbA1c evidence is limited, and the studies involved fewer than 100 people each.
- Best evidence:
Silk amino acid (SAA)
Silk amino acids are the building blocks of silk protein, including sericin from silkworm cocoons, and they supply amino acids like serine that the body uses to build its own proteins. People mostly look at them for skin hydration, and lab studies found sericin binds water and holds moisture well, though the evidence is very limited. Nearly all of this came from cell and animal work or cosmetic research, with no human trials of oral supplements, so what it does when swallowed remains unknown.
- Best evidence:
Soy Isoflavones
Soy isoflavones are plant compounds from soybeans that act as phytoestrogens, binding estrogen receptors, especially the beta type, to give a mild estrogen-like effect. People mostly look at them for menopause symptoms, where the evidence is strong, and a pooled analysis of randomized trials found bone mineral density improved. The bone evidence is moderate, and findings that blood calcium and IGF-1 went up were small and limited.
- Best evidence:
Spermidine
Spermidine is a compound found in foods like wheat germ, aged cheese and soybeans, and cells use it to support growth and to switch on their internal cleanup process. In population studies, people whose diets contained more of it had 24% lower mortality and 26% lower dementia risk. The evidence is limited, though: those studies only observed eating habits, and the small memory and blood pressure trials were early.
- Best evidence:
Tea Tree Oil
Tea tree oil is an essential oil from the leaves of an Australian tree, with plant compounds that disrupt the membranes of fungi and other microbes. People mostly look at it for nail fungus, and the evidence is limited: trials in fungal infections found symptoms eased and appearance was similar to an antifungal cream, though the fungus cleared less often than with medicine. The studies were small, with about 200 people at most.
- Best evidence:
Thai Ginseng
Thai ginseng, also called Kaempferia parviflora, is a ginger-family root whose plant compounds, called polymethoxyflavones, seem to influence energy use and blood flow. The evidence is moderate for body fat: three trials in overweight adults found reductions in body fat, including belly fat, over about 12 weeks. Those studies were small, roughly 240 people combined, and findings for strength or erectile function are more limited.
- Best evidence:
Tulsi
Tulsi, also called holy basil, is a leafy herb used for centuries in Ayurvedic practice, traditionally valued as an adaptogen that helps the body respond to stress. People mostly look at it for generalized anxiety, and the evidence is limited: in one small trial of 35 people, anxiety symptoms improved. That is a single study with few participants, so it says little about who would benefit or for how long, and larger trials are needed to confirm it.
- Best evidence:
ZMA
ZMA is a combination of zinc, magnesium and vitamin B6, nutrients the body uses for enzyme activity, muscle function and hormone signaling. The evidence is limited for sleep quality, where trials of the magnesium part found modest improvements, especially in older adults and people low in magnesium, though that benefit belongs to magnesium generally, not ZMA itself. Independent trials in well-nourished trained men found no clear difference in testosterone, strength or body composition.
- Best evidence:
American Ginseng
American ginseng is a root from a North American plant whose active compounds, called ginsenosides, are thought to influence immune activity and how the body handles stress and sugar. People most often look at it for colds, and the evidence is moderate: studies of a standardized extract found colds were less common and symptoms didn't last as long. Those results came from a few hundred people and mostly one branded extract, while findings for blood sugar and working memory were smaller and more limited.
- Best evidence:
Anthocyanins
Anthocyanins are the pigments that give blueberries, blackcurrants and red cabbage their deep purple and red colors, and they act as antioxidants in the body. People mostly look at them for thinking and memory, but a small trial of 14 people found no effect on verbal memory or working memory. The evidence is very limited, since so few people took part, so these results say little about how they might work for others.
- Best evidence:
Apigenin
Apigenin is a flavonoid, a natural plant pigment found in chamomile, parsley and celery. People mostly look at it for mood and sleep, and anxiety symptoms decreased moderately in trials of a chamomile extract containing apigenin, involving 179 people, though the evidence is limited. Those studies tested the whole extract rather than apigenin alone, and sleep gains were small, so it is hard to say how much apigenin itself contributed.
- Best evidence:
Aspartate
Aspartate is an amino acid the body uses to build proteins and pass signals between nerve cells, and its D form helps regulate hormone release. In a small group of untrained men, testosterone rose 42% over 12 days, and a combination with ubiquinol and zinc improved sperm motility over three months, though the evidence is limited. In resistance-trained men, testosterone did not rise and fell, and a review found no change in body composition.
- Best evidence:
Baikal Skullcap
Baikal skullcap is a flowering herb whose root contains flavonoids, such as baicalin, that are thought to influence calming brain signaling and inflammation. People mostly look at it for low mood, but the research for depression symptoms is very limited: one trial of 177 people found no clear difference in depression or anxiety symptoms. That trial tested it combined with saffron rather than on its own, so it says little about skullcap by itself, and more studies are needed.
- Best evidence:
Beef Protein
Beef protein is a powder made from beef that supplies the amino acids muscles use to build and repair tissue. The evidence is moderate that people gained more lean mass and lower-body strength than with no extra protein, and results matched whey. One small study found muscle building was lower than with whey in the first two hours after exercise, though over five hours there was no difference.
- Best evidence:
Betalains
Betalains are the red-violet and yellow pigments in beetroot and a few other plants, and they act as antioxidants in the body. In small trials, runners finished 5-10km efforts about 2-3% faster with a lower heart rate and perceived effort, and muscle damage markers returned to baseline within a day after exercise. The evidence is limited, though, and the blood pressure benefits of beetroot seem to come from its nitrate rather than betalains.
- Best evidence:
Black Pepper
Black pepper is a common spice whose active compound, piperine, gives it its bite and slows some of the enzymes your body uses to break down nutrients. People mostly look at it to help the body absorb other compounds, and studies found it raised absorption of curcumin, CoQ10, beta-carotene, selenium, vitamin B6 and resveratrol, with the evidence rated moderate. Findings on inflammation and metabolic rate were limited, and most studies were fairly small.
- Best evidence:
Brassinosteroids
Brassinosteroids are steroid-like hormones made by plants, where they help control growth, and researchers have studied them for possible effects in animals. The best-supported finding is for muscle: in rats, a brassinosteroid called 28-homobrassinolide increased muscle protein synthesis and improved lean body mass, without touching androgen-sensitive tissues. Still, the evidence is very limited, coming mostly from animal and lab studies, with no human trials behind it.
- Best evidence:
Butea Monosperma
Butea monosperma is a tropical tree, nicknamed flame of the forest, whose flowers and bark are used in traditional medicine and contain antioxidant flavonoids. People mostly look at it for bone health, and the evidence is limited: plant compounds encouraged bone-building cells to mature in lab studies and preserved bone density in rats modeling menopause. Nearly all of it was lab or animal work, so human results remain unknown.
- Best evidence:
California Poppy
California poppy is a golden-flowered plant whose extracts contain alkaloids that appear to act on calming pathways in the brain, including GABA and serotonin receptors. People mostly look at it for anxiety, but the evidence is limited: a trial of about 264 people found a combination product with hawthorn and magnesium eased mild to moderate anxiety. Because that product was a blend, and the other findings come mostly from rodents and lab work, it's unclear what California poppy does on its own.
- Best evidence:
China Rose
China rose, also called hibiscus, is a flowering shrub whose leaves and flowers are rich in anthocyanins and flavonoids, plant pigments with antioxidant properties, and it has a long history in traditional Ayurvedic use. People mostly look at it for hair growth, and in rodents, extracts applied to the skin increased hair follicle numbers and hair length. Nearly all of this work was in animals or lab dishes, no human trials exist, and the evidence is very limited.
- Best evidence:
Citric Acid
Citric acid is the sour acid in citrus fruit, and your body makes it while turning food into energy. People mostly look at it for kidney stones, and in human trials citrate salts, especially potassium citrate, meant fewer recurrences of calcium stones, so the evidence is moderate. Much of that work used citrate salts rather than plain citric acid, and evidence for bone health and sprint performance is limited and mixed.
- Best evidence:
Damiana Leaf
Damiana is a leafy shrub from Central and South America that contains apigenin, a plant compound known to act on the brain's calming GABA-A receptors. Human research is very limited: one study found a blend of damiana, yerba mate and guarana delayed stomach emptying and led to weight loss in overweight people, though damiana alone can't be credited. Everything else, like more sexual behavior in tired rats, comes from animal or lab work.
- Best evidence:
Dandelion
Dandelion is a common yellow-flowered plant whose leaf has traditionally been used as a diuretic, meaning it may make the body pass more urine. People mostly look at it for fluid retention, and the evidence is limited: in one small study of 17 people, urination went up over a single day. That study was brief and looked at urine output rather than swelling, so any benefit for fluid retention remains unclear.
- Best evidence:
Dang Shen
Dang Shen is the root of Codonopsis pilosula, a herb used for centuries in traditional Chinese medicine as a tonic, and it contains polysaccharides that appear to interact with immune cells. With no main use established, the best-supported finding is about immune function, where lab and animal studies found the polysaccharides boosted immune cell activity, including macrophages and cytokine production. Still, the evidence is very limited: this work is mostly animal or lab-based, and no controlled human trials have confirmed it.
- Best evidence:
Dwarf morning glory
Dwarf morning glory is a small creeping herb used for centuries in Ayurvedic medicine, where it is often sold as shankhpushpi, and it appears to act on the brain's chemical signaling. People mostly look at it for memory and learning, and in rodents an extract improved both, with effects comparable to a known memory drug. Even so, the evidence is limited, since it comes almost entirely from animal work and no human trials were found.
- Best evidence:
Eucommia Bark
Eucommia bark comes from a tree native to China and has long been used in traditional herbal medicine, where its plant compounds are thought to help relax blood vessels. People mostly look at it for high blood pressure, and the evidence is limited, though blood pressure came down in the research so far. That rests on a small group of 54 participants, so it is too early to say how far the results apply.
- Best evidence:
Fadogia agrestis
Fadogia agrestis is a shrubby plant from West Africa whose stem extract has long been used in traditional medicine, though its role in the human body is not established. People mostly look at it for testosterone and sexual function, and rat studies found higher testosterone and more sexual behavior, though the evidence is very limited. Nothing has been tested in humans, and at higher doses the rats showed testicular tissue damage.
- Best evidence:
Fang Ji
Fang Ji is a root from the Stephania tetrandra plant, used in traditional Chinese herbal medicine, that contains tetrandrine, a compound thought to influence inflammation and calcium movement in cells. In people with rheumatoid arthritis, markers of oxidative stress went down, though the evidence is limited. That came from one small study of 25 people, and lymphocyte counts showed no clear difference.
- Best evidence:
Felty Germander
Felty germander is a Mediterranean herb used in traditional remedies, and its main compounds are converted by a liver enzyme into reactive byproducts. The best-documented finding is harm: case reports described acute hepatitis, liver failure and deaths after people ingested it, leading France to ban products in 1992, though the evidence is limited. Hints of lower blood sugar, less inflammation and antioxidant activity came only from rodent and lab work.
- Best evidence:
Glutathione
Glutathione is an antioxidant your cells build from three amino acids, helping neutralize damaging molecules and supporting immune cells. Research on immune health is limited: in one trial of 52 people, antioxidant enzyme levels went up, and so did natural killer cell activity, a measure of immune defense. Beyond that, a separate study of 39 people found no clear difference in DNA damage.
- Best evidence:
Gluten
Gluten is a group of proteins in wheat, barley, and rye that gives dough its stretch, and it is not an essential nutrient. Research is clearest in celiac disease, where strong evidence showed gluten damaged the lining of the small intestine and disrupted nutrient absorption. Some people without celiac disease reported gut symptoms, but that evidence is limited, and none showed healthy people benefit from avoiding it.
- Best evidence:
Histidine
Histidine is an amino acid the body uses to build proteins, including hemoglobin, and to make carnosine, a compound that helps buffer and protect muscle. Most interest centers on blood health, where small human studies suggested it may have improved iron status and iron absorption in iron-deficiency anemia, though the evidence is very limited. Much of the support comes from animal and lab work, and no large trials have tested it in people.
- Best evidence:
Hordenine
Hordenine is a plant compound found in barley and beer, chemically related to tyramine, that can influence dopamine and noradrenaline signaling. In lab work it activated dopamine D2 receptors, but when four people drank beer, their blood levels stayed too low to reach those receptors and faded within about an hour. Overall the evidence is very limited, and most findings come from animal or lab studies, not human trials.
- Best evidence:
Isoleucine
Isoleucine is an essential amino acid, one the body cannot make, that cells use to build proteins and handle energy. People mostly look at it for blood sugar, and the evidence is limited: across several rodent studies, blood glucose fell by about 20% as muscle tissue took up more sugar. Nearly all of this came from animal or lab work, so it is still unclear whether people would see the same effect.
- Best evidence:
Japanese catnip
Japanese catnip is an aromatic herb from the mint family, used for centuries in traditional East Asian medicine and rich in plant compounds such as flavonoids that interact with the body's immune signaling. Research has looked most at inflammation, where lab and animal studies found the extract lowered inflammatory signals such as TNF-alpha and IL-6 in immune cells. The evidence is very limited, though: nearly all of it comes from cells and animals, and no human trial results were reviewed here.
- Best evidence:
Kaempferol
Kaempferol is a flavonol, a plant compound found in tea, kale, broccoli and other vegetables, where it acts as an antioxidant and helps switch inflammatory signals on and off in cells. People mostly look at it for its possible anti-cancer and anti-inflammatory effects, and lab studies found it slowed the growth of breast, prostate and colon cancer cells. Almost all of that work was done in cells and animals, no human trials have tested it, and the evidence is very limited.
- Best evidence:
Kokilaksha
Kokilaksha, also known as Asteracantha longifolia, is a herb long used in Ayurvedic tradition. The best-supported finding is for the liver: in animal studies, its extracts reduced markers of liver damage, though the evidence is very limited. No human trials have tested this, and the same is true of early lab hints at antioxidant effects and its traditional reputation as an aphrodisiac.
- Best evidence:
Kratom
Kratom is a leaf from a Southeast Asian tree whose main compounds, mitragynine and 7-hydroxymitragynine, partly activate the brain's opioid receptors. People mostly look at it for pain relief, and surveys and reviews reported relief, but the evidence is very limited because no rigorous human trials have tested it. Reviews and case reports also found that regular use led to physical dependence and opioid-like withdrawal.
- Best evidence:
Maral root
Maral root is the plant Rhaponticum carthamoides, traditionally used as an adaptogen and rich in ecdysteroids, plant compounds that seem to influence how muscle cells build protein. The best-supported findings are for stress resilience: in tiny roundworms, the extract and its main compound, 20-hydroxyecdysone, improved heat tolerance and movement, and extended lifespan. The evidence is very limited, though, since it comes mostly from worm, rodent and lab-dish work, with no quality human trials.
- Best evidence:
Massularia acuminata
Massularia acuminata is a West African shrub whose twigs are traditionally chewed as natural toothbrushes. In one small six-week trial of 60 Nigerian schoolchildren, gum health improved slightly with the chewing sticks compared with toothbrushes, but the differences were not statistically significant. Other findings come mostly from rats, where testosterone and libido-related behavior rose, though liver damage appeared too, and no human studies exist.
- Best evidence:
Mondo grass
Mondo grass (Ophiopogon japonicus) is an evergreen plant whose root is used in traditional Chinese medicine and contains saponins, homoisoflavonoids and polysaccharides. People look at it mostly for its possible anti-inflammatory effects, and lab and animal studies found extracts calmed inflammation, though the evidence is very limited. Similar early work pointed to heart, immune and antioxidant activity, but nearly all of it came from animals or test tubes, and no human trials on the herb alone have confirmed any of it.
- Best evidence:
N,N-Dimethyltryptamine
N,N-Dimethyltryptamine (DMT) is a psychedelic compound found in many plants that acts on serotonin signaling in the brain. Human studies found it produced intense, short-lasting psychedelic experiences, with visual hallucinations and deeply altered consciousness, and lab work pointed to the 5-HT2A serotonin receptor as the main driver, though the evidence is very limited. Hints of antidepressant effects came mostly from ayahuasca, which pairs DMT with another compound, and from animal or lab studies.
- Best evidence:
Phosphatidylcholine
Phosphatidylcholine is a fat-like molecule that helps build the membranes surrounding every cell, including liver cells, where it supports repair and normal function. People mostly look at it for general liver health, and the evidence for that use is moderate. Still, the research summarized here did not include specific liver results, and cholesterol measures in 152 people, HDL and LDL, showed no clear difference.
- Best evidence:
PRL-8-53
PRL-8-53 is a synthetic compound, not a nutrient, that researchers have explored for its possible effects on how the brain handles learning and recall. People mostly look at it for cognitive improvement, and the evidence is limited: in research with 47 people, memory improved. That is a small group, and motor control showed no clear difference, so the picture is far from settled.
- Best evidence:
Punarnava
Punarnava, also called Boerhaavia diffusa, is a herb used for centuries in Ayurvedic medicine, and its plant compounds are thought to act on fluid balance, the liver and immune cells. People mostly look at it for swelling and fluid retention, and rodent studies found extracts increased urine output, though the evidence is very limited. No human trials have tested this, and the other findings, on liver markers, immune activity and cancer cells, came from animal or lab work.
- Best evidence:
Pyritinol
Pyritinol is a lab-made compound built from two linked vitamin B6 molecules, sold as a nootropic rather than as a nutrient. The evidence is limited, but it is strongest for memory and thinking in older people, where several European studies found modest improvements in cognitive function. Those studies were small, often old and weakly designed, and none tested healthy young adults, despite the marketing.
- Best evidence:
Sage
Sage is a culinary herb whose leaves hold plant compounds such as rosmarinic acid, carnosic acid and carnosol, which show antioxidant activity in lab work. People mostly look at it for menopausal hot flashes, and several human studies found that sage extract made them less frequent and less intense, though the evidence is limited to moderate. Those studies were small, and the memory findings, which suggested modest gains in memory and attention, come from small, short studies too.
- Best evidence:
Silica
Silica is a form of silicon, a trace mineral in connective tissue thought to help build skin, bone, and hair. People mostly look at it as supportive care for hair-pulling disorder, and the evidence is limited: small human trials of a stabilized form found modest gains in hair strength and less brittle nails. The gains were modest and the studies small, so they say little about hair-pulling itself.
- Best evidence:
Slippery Elm
Slippery elm is the inner bark of a North American tree, rich in mucilage, a gel-like fiber that coats and soothes the throat and gut. People mainly look at it for digestive complaints and sore throat, yet the evidence is limited, and no controlled trials have tested it alone for either. Existing research is mostly lab work on herbal extracts that found antioxidant compounds, which says little about how people feel.
- Best evidence:
Squalene
Squalene is an oily compound the body makes on the way to cholesterol, and it is also a major part of the natural oils on human skin. Most interest centers on cholesterol and heart health, where 15 of 18 animal studies found better blood fat profiles, but only one of three human studies did. The evidence is very limited and mostly animal or lab work, so it's unclear how well it applies to people.
- Best evidence:
Sunifiram
Sunifiram is a lab-made compound, related to the racetam family, that appears to boost signaling through glutamate receptors, which are central to learning and memory. Its best-supported finding is in rodents, where memory loss induced by a drug was less severe in maze and avoidance tests, at roughly 1,000 times the potency of piracetam. Still, the evidence is very limited: it comes entirely from animal and lab work, and no human studies exist.
- Best evidence:
Yeast Mannan
Yeast mannan is a fiber-like carbohydrate from yeast cell walls that feeds gut microbes and interacts with immune cells in the gut. Most interest centers on immune function, where the evidence is limited: studies in fish, mice, and poultry found stronger innate immune responses and better reactions to infectious challenges. All of that work was in animals, and no human trials exist, so results may not carry over to people.
- Best evidence:
Alanine
Alanine is an amino acid your body uses to build proteins and to shuttle nitrogen and fuel between muscle and liver, where it helps make glucose. With no main use established, the best-supported finding is about blood sugar: in diabetic rats, alanine supplements improved blood glucose, and lab work showed it switched on an energy-sensing enzyme in liver cells. The evidence is very limited, though, because it comes almost entirely from animal and lab studies and no human supplementation trials exist.
- Best evidence:
Althaea Officinalis
Althaea officinalis, better known as marshmallow root, is a plant whose roots and leaves contain a gel-like fibre that coats and soothes the lining of the mouth and throat. Most people look at it for cough, and studies found symptoms eased within minutes and stayed better over a week, though the evidence is limited. Much of that came from observational surveys, and the evidence in children and in a small placebo comparison is very limited, partly because the preparations were poorly described.
- Best evidence:
Aniracetam
Aniracetam is a lab-made compound from the racetam family that is thought to influence glutamate signaling, a chemical system involved in learning and memory. In people with mild dementia, research found thinking scores held steady over 6 to 12 months, did better than cholinesterase inhibitor drugs at 6 months, and mood and daily functioning improved at 3 months. Still, the evidence is limited, drawn from about 276 people, with effects small to moderate.
- Best evidence:
Banana Flower
Banana flower is the purple blossom of the banana plant, eaten as a vegetable in parts of Asia and rich in fiber and plant compounds. In a double-blind trial of 50 adults with prediabetes, banana biomass supplementation lowered body weight and BMI, and diastolic blood pressure also fell. Still, the evidence is limited, coming from a small study of a banana-based product, and it is very limited for blood sugar.
- Best evidence:
Biotin (Vitamin B7)
Biotin is a B vitamin the body uses to make keratin, the protein in hair, skin and nails, and to turn food into energy. People mostly look at it for nail health, where the evidence is moderate, but the trial results available here come from progressive multiple sclerosis, where symptoms showed no clear difference. That evidence is very limited, covering four studies and 360 people, so it says little about nails.
- Best evidence:
Black Currant
Black currant is a dark berry rich in anthocyanins and vitamin C, plant compounds that act as antioxidants and may influence how blood vessels relax and stretch. People mostly look at it for heart and blood-vessel health, but the evidence is very limited: one small study of 45 people found no clear difference in arterial stiffness or pulse wave velocity. Because that is a single small trial, it says little about longer use or other groups, and more research is needed.
- Best evidence:
Burning Bush
Burning bush (Euonymus alatus) is a shrub whose twigs and extracts are used in traditional herbal medicine, and it contains flavonoids such as quercetin that act as plant antioxidants. People mostly look at it for blood sugar, and lab work found its extracts blocked an enzyme that helps digest carbohydrates, while in diabetic rats the extract lowered blood glucose after a starch meal. The evidence is very limited: the effect was not especially strong compared with established options, and no human studies back it up.
- Best evidence:
Caesalpinia Benthamiana
Caesalpinia benthamiana is a plant whose root has long been used in traditional medicine, and lab work suggests it may influence nitric oxide, a molecule that relaxes blood vessels. People mostly look at it for sexual function, and in rats the root extract increased mounting and intromission and delayed ejaculation. The evidence is very limited, though: no human trials exist, and cell studies showing more nitric oxide synthase are only a possible explanation.
- Best evidence:
Calcium Caseinate
Calcium caseinate is a milk protein, made by binding casein to calcium, that supplies amino acids the body uses to build and repair muscle. People mostly look at it for muscle size and strength, and the evidence is moderate: it stimulated muscle protein synthesis about as well as whey over 24 hours, and gains alongside resistance training were similar. Evidence for appetite is limited, with some studies finding it filled people up more than whey.
- Best evidence:
Charcoal
Charcoal, usually activated charcoal, is a fine, porous carbon powder that binds substances in the gut so they leave in stool instead of entering the blood. Its best-supported role is in emergency medicine for acute poisoning, including arsenic, where the evidence is strong and large groups of people were studied. Outside the emergency room, the evidence is limited: small studies found lower uremic toxins in kidney disease and modest LDL cholesterol drops, though kidney outcomes were mixed.
- Best evidence:
Creatinol O-Phosphate
Creatinol O-phosphate is a compound related to creatine that heart muscle cells can use in their energy metabolism. People mostly look at it for heart rhythm problems, and human trials from the late 1970s found that injected doses reduced extra ventricular beats in people with ischemic heart disease, with moderate evidence. Those studies were small, all used injections rather than oral forms, and the other heart findings rest mostly on animal or lab work.
- Best evidence:
Devil's Claw
Devil's claw is a plant from southern Africa whose dried root contains compounds, such as harpagoside, thought to calm inflammation in the body. People mostly look at it for chronic low back pain, and the evidence is moderate: three studies found osteoarthritis symptoms improved. Those studies were small, involving 167 people in total, and some were early pilot trials, so the findings are a promising starting point rather than a final answer.
- Best evidence:
Kutki
Kutki is a bitter Himalayan herb, used for centuries in Ayurvedic medicine, whose root contains compounds thought to calm inflammation in the liver. People mostly look at it for recovery from acute viral hepatitis, and a small trial found that bilirubin went down and liver enzymes improved, though the evidence is limited. That trial included only 33 people, so the findings are early and can't tell us how well it works more broadly.
- Best evidence:
Neem
Neem is an evergreen tree from India whose leaves, bark and oil have long been used in traditional medicine, and its plant compounds have antibacterial and anti-inflammatory properties. People mostly look at it for gum health, and small studies found neem mouthwash lowered plaque scores about as much as chlorhexidine and modestly eased gum inflammation. Still, the evidence is limited, the trials were small, and evidence for skin uses like acne is very limited.
- Best evidence:
Pedalium murex
Pedalium murex is a flowering herb whose fruit has long been used in traditional medicine. Research has looked most at kidney stones, where animal and lab studies found the fruit extract reduced calcium oxalate crystal buildup and blocked struvite crystal formation, though the evidence is limited. Because this work is mostly animal or lab-based, it is still unclear whether people would see the same effects.
- Best evidence:
Phenylethylamine
Phenylethylamine (PEA) is a compound your body makes naturally, where it helps release dopamine and norepinephrine and is linked to mood regulation. People mostly look at it for mood, but no clinical trials of PEA supplements have been run, so the evidence is very limited. Oral PEA is broken down within minutes by an enzyme called MAO-B, so very little appears to reach the brain, and the mood, focus and exercise ideas rest on mechanism alone.
- Best evidence:
Pine Pollen
Pine pollen is a fine powder collected from pine trees, containing plant compounds such as flavonoids and phenolic acids. People look at it for testosterone, but no human studies found an increase, and its androgen content is far below what the body makes. Lab and animal work suggested antioxidant activity and lower inflammatory markers, yet the evidence is very limited and no human trials have tested whether swallowing it does the same.
- Best evidence:
Pumpkin Seed Extract
Pumpkin seed extract comes from the seeds of the pumpkin plant and is thought to work by slowing 5-alpha reductase, an enzyme that turns testosterone into a stronger hormone. The strongest findings involve enlarged prostate, where pooled trials found modest gains in urinary symptoms and flow, smaller than with finasteride, and the evidence is moderate. Hair growth and overactive bladder findings rest on very few studies, so that evidence is limited.
- Best evidence:
Red Berry Powder
Red berry powder is a dried blend of berries such as strawberries, raspberries and cranberries, rich in anthocyanins, plant pigments that act as antioxidants. People mostly look at it for antioxidant status, and studies of individual berries found these compounds raised antioxidant capacity in blood, though the evidence is very limited. Mixed blends themselves have not been tested in clinical trials, so hopes for heart health and memory rest on single-berry research.
- Best evidence:
Red Paprika Extract
Red paprika extract is a concentrate of the red carotenoid pigments in peppers, chiefly capsanthin, which can act as antioxidants in the body. Antioxidant activity is the main interest, and lab studies found capsanthin and related carotenoids mopped up free radicals, though the evidence is very limited. Most of that work was done in lab settings, and no human trials have tested the extract itself.
- Best evidence:
Rhamnus nakaharai
Rhamnus nakaharai is a plant in the buckthorn genus, used in Taiwanese folk medicine, that contains quercetin glycosides, which are plant antioxidants. People have traditionally used it for constipation, but no clinical studies have tested it for that, so the evidence is very limited. Its relative cascara has known laxative effects, and quercetin has shown anti-inflammatory effects in lab work, but those findings come from other species or isolated compounds, not this plant.
- Best evidence:
Rosemary Oil
Rosemary oil is an aromatic essential oil from the rosemary plant, rich in compounds like 1,8-cineole that can be absorbed through the skin or inhaled. Its best-studied use is hair loss from androgenetic alopecia, where one six-month trial of 100 people found hair counts rose about as much as with minoxidil, though itching was more common early on. Since that is a single trial, the evidence is limited.
- Best evidence:
Rosmarinic Acid
Rosmarinic acid is a plant compound found in rosemary, perilla and other herbs, where it acts as an antioxidant and helps calm inflammatory signaling in the body. People mostly look at it for seasonal allergies, and in a small trial of 29 people, allergy symptoms and nasal congestion both eased, though the evidence is limited. That is only one small study, so it is too early to say how well the results hold up or who they apply to.
- Best evidence:
Salt
Salt is sodium chloride, a mineral compound whose sodium helps balance fluids and carry nerve and muscle signals. People with cystic fibrosis mainly look to it to replace salt lost in sweat, and the evidence for that use is strong. Trials found higher intake raised blood pressure, especially in salt-sensitive people, though large studies linked very low intake to worse heart outcomes too.
- Best evidence:
Sodium Oligomannate
Sodium oligomannate is a seaweed-derived mix of short sugar chains that seems to act through the gut, changing the bacteria there in ways that may calm inflammation linked to the brain. People mostly look at it for Alzheimer's disease, and the evidence is limited: a 36-week trial found thinking scores improved more than with placebo, but a smaller earlier trial did not reach significance. Everyday function and clinician ratings showed no clear gain in the larger trial, and the gut and inflammation findings come mostly from mouse studies.
- Best evidence:
Turkey tail mushroom
Turkey tail is a mushroom whose beta-glucan fibers are thought to stir up immune cells such as natural killer cells and macrophages. People mostly look at it as supportive care during breast cancer treatment, and the evidence is moderate overall, though in the one small trial reviewed, lymphocyte counts went up while natural killer cell activity showed no clear difference. That study was a early-stage trial of just nine women, so the findings are very preliminary.
- Best evidence:
Whole Coffee Fruit Extract
Whole coffee fruit extract comes from the red fruit around the coffee bean, and it is rich in plant compounds like chlorogenic acid that may influence how brain cells signal and grow. People mostly look at it for memory and thinking in adults with age-related slips, and the evidence is limited: two industry-affiliated trials found better working memory and reaction time, but the only independent trial found no cognitive benefit and more mental fatigue. Studies were small and short, and the brain-protection findings rest mostly on animal or lab work.
- Best evidence:
1,3-Dimethylamylamine
1,3-Dimethylamylamine, often called DMAA, is a stimulant compound that acts on the nervous system and appears in some pre-workout products, with no nutritional role in the body. In a small study of healthy adults, blood pressure went up moderately, an unwelcome effect, while heart rate showed no significant change. That work involved only about ten people, so the evidence is very limited and says little beyond that.
- Best evidence:
Agmatine
Agmatine is a compound the body makes from the amino acid arginine, and it acts as a signaling molecule in the nervous system. With no single main use standing out, the best-supported finding is for nerve-related pain from a pinched lumbar disc, where one trial found a moderate improvement in pain. That evidence is limited, though, since it comes from one small study of 61 people. For depression, only a tiny case series of three people has been reported, so it is very preliminary.
- Best evidence:
Bulbine Natalensis
Bulbine natalensis is a succulent plant native to southern Africa, and its extracts are sold as a supplement, though it is not a nutrient the body needs. Research on metabolic health is very limited so far: the only result available looked at kidney function, and it found no clear difference in 36 people. That is a small group and a single result, so it says little about whether the plant does anything else.
- Best evidence:
Butterbur
Butterbur is a shrub whose root extract contains petasins, compounds that block histamine receptors and slow the body's production of inflammatory leukotrienes. People mostly look at it for hay fever, and trials found seasonal allergy symptoms eased about as much as with cetirizine, without sedation. The evidence is strong overall but moderate for symptoms specifically, and one migraine trial also found fewer attacks than placebo.
- Best evidence:
Cangfu Daotan Decoction
Cangfu Daotan Decoction is a traditional Chinese herbal formula, made from several plants and used for irregular cycles. In women with polycystic ovary syndrome and infertility, meta-analyses of Chinese trials found that adding it to clomiphene gave higher ovulation and pregnancy rates than clomiphene alone. The evidence is limited, though, since the trials varied widely, carried a risk of bias, and were of low quality.
- Best evidence:
Caralluma Fimbriata
Caralluma fimbriata is a succulent plant traditionally eaten in India, and its extract is sold as a supplement thought to influence hunger signals in the body. People mostly look at it in the context of being overweight, and the strongest finding is limited: in one small study of 50 adults, appetite went down. That same study found no clear difference in weight, and with only one small trial behind it, the picture is far from settled.
- Best evidence:
Cat's claw
Cat's claw is a woody vine from the Amazon rainforest, and its bark has long been made into teas and extracts that are thought to influence how immune cells behave. People mostly look at it for immune health, and in the one small study reviewed here, white blood cell counts went up, though the evidence is limited. That study involved only four participants and tested a specific extract, so it can't tell us whether the finding would hold for other people or other products.
- Best evidence:
Centrophenoxine
Centrophenoxine is a compound made from DMAE and a plant-growth-hormone-like acid, and it is thought to support the brain's cell membranes and neurotransmitter building blocks. People mostly look at it for cognitive function, and older studies in elderly people with cognitive decline found improvements in memory, attention, and mental clarity, though the evidence is limited. Those studies date from the 1960s to 1980s and fall short of modern quality standards, and work on lipofuscin, a cellular aging marker, came mostly from animal or lab studies.
- Best evidence:
Chinese sweet leaf
Chinese sweet leaf is a Rubus plant, a relative of raspberry, whose leaves are brewed into a naturally sweet tea and contain plant compounds called polyphenols. People mostly look at it for allergy symptoms, but the evidence is very limited: one placebo-controlled trial of 89 people with dust mite allergy found no clear difference in symptoms or nasal congestion. It was a single small study, so it is too early to say more.
- Best evidence:
Chitosan
Chitosan is a fibre made from the shells of shellfish that binds to fats and bile acids in the gut, which is why it is sold as a weight and cholesterol aid. People mostly look at it for weight loss, and meta-analyses found they lost about 1.7 to 2 kilograms more than those on placebo over several weeks, though the evidence is limited. That difference was statistically significant but clinically modest, and cholesterol showed a similarly small drop in the studies reviewed.
- Best evidence:
Chondroitin
Chondroitin is a natural part of cartilage, the cushioning tissue in joints, where it helps hold water and structure. People mostly look at it for joint pain, and the evidence is moderate: a pooled analysis of about 3,800 people with knee osteoarthritis found pain improved. The gains were small, though, and trials did not always agree, so the findings mostly apply to osteoarthritis.
- Best evidence:
Coffee Pulp Extract
Coffee pulp extract comes from the fleshy fruit around the coffee bean and is rich in polyphenols, plant compounds with antioxidant activity in the lab. In one small study of 25 people, blood levels of BDNF, a protein that supports nerve cells, rose more after coffee fruit concentrate than after caffeine or placebo. That came from one industry-funded trial not yet repeated, and the antioxidant work is lab-only, so the evidence is very limited.
- Best evidence:
Dactylorhiza hatagirea
Dactylorhiza hatagirea is a Himalayan orchid whose tuberous root has long been used in Ayurvedic medicine as a tonic, known as Salabmisri. People mostly look at it as a traditional aphrodisiac, and two rodent studies found extract increased mounting and other sexual behavior in male rats. The evidence is very limited: this is animal work only, it did not beat other Ayurvedic herbs, and its effects on testosterone were small.
- Best evidence:
DMAE
DMAE (dimethylaminoethanol) is a compound related to choline, a nutrient the body uses to build the messenger chemical acetylcholine, which nerve cells rely on for memory and learning. People mostly look at it for cognitive decline, and a single trial of 241 people with suspected early Alzheimer's disease found no clear difference after six months. The evidence is very limited, since that one study tested a particular DMAE-based formulation, so it says little about DMAE on its own.
- Best evidence:
Electric Nerve Stimulation
Electric nerve stimulation uses a small device to send mild electrical pulses through the skin, which is thought to interrupt pain signals traveling along nerves and to nudge the body's own pain-dampening pathways. People mostly look at it for chronic pain, and trials found pain intensity went down by a moderate amount compared with placebo, and also compared with standard care treatments. Even so, the evidence is limited, and the results came mainly from the period during or just after treatment, so they say little about lasting relief.
- Best evidence:
Epigallocatechin Gallate
Epigallocatechin gallate, or EGCG, is the main catechin in green tea, a plant antioxidant that interacts with enzymes and inflammatory signaling in the body. People mostly look at it for metabolic health, and the evidence there is very limited: one review covering 152 people found no clear difference in C-reactive protein, and a small group of 44 saw no clear change in interleukin 6. Both are inflammation markers, and the research is too thin to say much beyond that.
- Best evidence:
Fennel
Fennel is an aromatic plant whose seeds are used as a spice and traditional remedy, and they contain anethole, a compound thought to ease gut muscle spasms and act a little like estrogen. People most often look at it for infant colic, where the evidence is moderate and some research found colic symptoms eased. For breast milk production the evidence is limited, so those findings are much less certain.
- Best evidence:
Glucuronolactone
Glucuronolactone is a compound the body makes naturally from glucose, involved in building connective tissue and in clearing substances through the liver, and it is also added to some energy drinks. Research has looked mainly at liver protection, and in rats and chicken liver cells it lowered markers of liver injury and inflammation. The evidence is very limited, though, because these were small animal and lab studies, so what they mean for people remains unknown.
- Best evidence:
Grains of Paradise
Grains of Paradise is a peppery seed from a West African plant related to ginger, used as a spice, and it contains compounds that may act on brown fat, the tissue that burns energy to make heat. People mostly look at it for body composition, and one small study found that the metabolic rate went up in men, though the evidence is limited. That trial included only 19 participants, so it says little about longer-term weight or body fat changes, or about how women might respond.
- Best evidence:
Hibiscus macranthus
Hibiscus macranthus is a flowering plant from West and Central Africa, used in traditional medicine, whose leaf and stem extracts have been studied for effects on male reproductive hormones. Research has centered on testosterone, and rat studies found that a blend with Basella alba raised testosterone levels and increased sperm production in the testes. The evidence is very limited, though: it comes almost entirely from animal and lab work, and no human trials were found.
- Best evidence:
King Oyster
King oyster is an edible mushroom that is a rich food source of ergothioneine, an antioxidant compound the body absorbs and uses to help protect cells from damage. People mostly look at it for skin health, and a small study of 77 people found skin quality improved, though the evidence is limited. Skin dryness showed no clear difference, and that finding rests on a single trial, so the evidence is very limited.
- Best evidence:
Laughter Yoga
Laughter yoga is a group practice that combines deliberate laughing exercises with yogic breathing, and it aims to lift mood by triggering the body's relaxation response. People mostly look at it for stress, but a trial in 83 nursing students found no clear difference in stress symptoms or in well-being, and the evidence is very limited. That is only one small study in one group of students, so it says little about how laughter yoga might work for other people or over longer periods.
- Best evidence:
Magnolia Bark Extract
Magnolia bark extract comes from magnolia tree bark and is rich in plant compounds called magnolol and honokiol, long used in traditional Asian herbal practice. Research has looked mostly at dental health, where one randomized trial of 120 people found that a sugar-free chewing gum containing it improved dental health measures. With just one trial, the evidence is limited, and the results apply to that gum rather than other forms.
- Best evidence:
Maitake
Maitake is an edible mushroom, used in cooking and traditional medicine, that contains beta-glucans, fibers known to interact with the immune system and to influence how the body handles sugar. People mostly look at it for blood sugar in type 2 diabetes, where small trials found a small drop in fasting glucose, though the evidence is limited. Blood pressure showed only a trend downward that was not statistically significant, and the studies were small, so firm conclusions aren't possible yet.
- Best evidence:
Methylliberine
Methylliberine is a caffeine-like compound found in small amounts in Kucha tea leaves, and it is thought to act on the brain's adenosine system, which shapes alertness. People mostly look at it for focus and reaction speed, and trials found that a blend with caffeine and theacrine improved reaction times in egamers and tactical personnel. The evidence is very limited: only a few small studies, it was never tested alone for reaction time, and its own contribution can't be separated out.
- Best evidence:
Milk Thistle
Milk thistle is a plant whose seed extract, silymarin, is thought to protect liver cells and support their regeneration. People mostly look at it for liver health, where the evidence is strong, but two trials on breast milk production found no clear difference in how much milk mothers made. Those studies were small, about 100 mothers combined, so the evidence there is very limited.
- Best evidence:
Oxytropis falcate
Oxytropis falcate is a flowering herb in the legume family, used in traditional Tibetan and Chinese medicine rather than as a nutrient the body needs. Researchers looked at it for pain and inflammation, and extract applied to the skin eased pain in a rat study and showed anti-inflammatory activity in a rodent model. The evidence is very limited, though: it is animal work only, with no human studies and nothing on swallowing it.
- Best evidence:
Raspberry Ketone
Raspberry ketone is the aroma compound that gives red raspberries their scent, and in lab work it appears to influence how fat cells handle stored fat. People mostly look at it for body fat, but the evidence is very limited: rats fed high-fat diets gained less fat, and isolated fat cells released more adiponectin. No human trials exist, so it is unclear whether any of this carries over to people.
- Best evidence:
Rauwolscine
Rauwolscine, also called alpha-yohimbine, is a plant compound that blocks alpha-2 adrenergic receptors, which normally brake the release of stress-signalling chemicals. People mostly look at it for fat loss, but no human trials have tested that, and lab binding studies only showed it blocks this receptor, possibly more strongly than yohimbine. The only other work was one 1964 study on the sympathetic nervous system, so the evidence is very limited and largely borrowed from yohimbine.
- Best evidence:
Sarcosine
Sarcosine is a natural amino acid derivative that blocks a glycine transporter in the brain, which helps nerve cells respond more fully at NMDA receptors. People mostly look at it as an add-on for schizophrenia, and trials found symptoms improved and thinking skills got better when it was added to antipsychotic medication. Each finding came from a single study, though, and the cognition result was small, so the picture is still taking shape.
- Best evidence:
Schisandra
Schisandra is a berry-bearing vine used in traditional herbal medicine as an adaptogen, a plant thought to help the body handle stress and to protect liver cells. People mostly look at it for support while recovering from acute viral hepatitis, and the evidence for that use is limited. Other research is small: one study of 71 people found nitric oxide went up, while cortisol results were mixed.
- Best evidence:
Tea (Camellia sinensis)
Tea comes from the leaves of the Camellia sinensis plant and supplies caffeine and l-theanine, compounds that influence alertness and calm. People mostly look at it for sharper thinking, and the evidence is strongest for reaction time, which got quicker in one study of 88 people. Attention also improved, though the evidence is moderate and the effect was small, and the studies involved healthy participants.
- Best evidence:
Uridine
Uridine is a building block of RNA that the body makes on its own and also gets from food, and it helps cells build membranes and produce the genetic material they need. People have mostly looked at it for bipolar disorder, where the small amount of research reviewed found that overall symptoms and depression symptoms improved. That evidence is limited, though: it comes from a single small study of just seven people, so it can't say how well uridine would work for others.
- Best evidence:
Alpha-Ketoglutarate
Alpha-ketoglutarate is a molecule your cells make during the Krebs cycle, the process that turns food into energy, and it also helps move nitrogen and build amino acids. In one study, biological age estimated from DNA methylation came out about eight years lower, but the evidence is very limited. Only 42 people took part and there was no placebo group, so the result can't show the supplement caused it.
- Best evidence:
Avocado/Soybean Unsaponifiables
Avocado/soybean unsaponifiables are plant extracts made from the oil-rich parts of avocado and soybean, and lab work suggests they calm inflammatory signals that break down cartilage in joints. People mostly look at them for osteoarthritis, and a review of placebo-controlled trials found symptoms eased, with moderate evidence behind that result. The findings came from a small body of research, about one study's worth of data on roughly 1,095 people with hip or knee osteoarthritis, so more trials would help firm things up.
- Best evidence:
Banaba Leaf
Banaba leaf comes from a tropical tree, Lagerstroemia speciosa, and contains compounds such as corosolic acid that are thought to help cells take up sugar from the blood. People mostly look at it for blood sugar in type 2 diabetes, and the one study found blood glucose came down, though the evidence is limited. That trial was tiny, with only five participants, so it shows a hint of promise rather than a clear answer.
- Best evidence:
Brassaiopsis glomerulata
Brassaiopsis glomerulata is a tree in the ginseng plant family, containing triterpene saponins, plant compounds that can interact with enzymes. Lab work has focused on aromatase, an enzyme that helps make estrogen, and saponins from the plant blocked it in cell-free and cell-based tests, though the evidence is very limited. No animal or human studies exist, and blocking an enzyme in a dish often fails to carry over to the body.
- Best evidence:
Butea Superba
Butea superba is a climbing plant from Thailand whose root has long been used in traditional medicine, and it contains plant compounds thought to act on hormone and blood-flow pathways. People mostly look at it for erectile function, but the evidence is very limited: two small studies with 70 people in total found no clear difference in erections. With so few participants and so little research, it is hard to say much about how it works in people.
- Best evidence:
Chrysin
Chrysin is a natural compound, a type of flavonoid, found in honey, propolis and passionflower, and it is studied for how it interacts with enzymes involved in hormone balance. People mostly look at it for low testosterone, but the research is thin: the one small study found no clear difference in testosterone, and the evidence is very limited. That study followed just 20 men and measured urinary testosterone, so it says little about longer use or other groups.
- Best evidence:
Cotton Seed
Cotton seed is the seed of the cotton plant, a source of oil and protein used in foods and animal feed. Research has looked at it mainly for breast milk production, and a small study of 45 women found milk production went up. Because the study was small and the evidence is limited, it is too early to say how well that result holds for other mothers.
- Best evidence:
Guarana
Guarana is a climbing plant from the Amazon whose seeds are rich in caffeine, a stimulant that blocks adenosine, the brain chemical that makes you feel drowsy. People mostly look at it for fatigue, but the evidence is very limited: a small study of 20 people found no clear difference in cognition. With so few participants, it is too early to say much either way, and the results may not carry over to everyone.
- Best evidence:
IP6
IP6, also called inositol hexaphosphate or phytic acid, is a compound found in grains, beans, and seeds that binds minerals and takes part in cell signaling. With no single main use established, the best-supported finding is about uric acid: in one small crossover trial of 25 people with high uric acid, blood levels went down, and the evidence is limited. That is a single short study, so it needs repeating in larger groups before anyone can say how far the result holds.
- Best evidence:
Jujube
Jujube is the sweet, datelike fruit of the Ziziphus jujuba tree, used for centuries in traditional Asian cooking and herbal practice and rich in plant compounds and fiber. People mostly look at it for constipation, and a small controlled trial of 37 people found their constipation symptoms improved. Because that is a single small study, the evidence is limited, and it says little yet about how well the results hold up in larger or more varied groups.
- Best evidence:
Lysine
Lysine is an essential amino acid, a protein building block the body can't make itself and needs for tissue growth and repair. People mostly look at it for canker sores, and the evidence there is limited. The one small study of cold sores, in 26 people, found no clear difference in how often they came back, so the evidence is very limited there too.
- Best evidence:
Malabar Spinach
Malabar spinach is a leafy climbing vine eaten as a vegetable in parts of Asia and Africa, valued for its vitamins, minerals and plant compounds. The evidence on it as a supplement is very limited: one rat study found that an extract combined with another plant raised testosterone levels, with Malabar spinach seeming the more active part. Since the plants were given together, its own effect is unclear, and no human studies exist.
- Best evidence:
Minoxidil
Minoxidil is a vessel-widening compound applied to the scalp, where it is thought to encourage hair follicles to keep growing. People mostly look at it for hair loss, and the evidence is strong: across 8 studies with 1,778 participants, hair regrowth improved. The size of the effect was moderate, and one key trial focused on men with pattern hair loss, so results may not apply equally to everyone.
- Best evidence:
Mucuna Pruriens
Mucuna pruriens is a tropical bean whose seeds naturally contain L-DOPA, the compound the brain converts into dopamine, the chemical messenger that helps coordinate movement. People mainly look at it for Parkinson's disease, and the evidence is rated strong: in three small studies, symptoms eased. Those studies enrolled only about 40 people in total, and some were short pilot or crossover designs, so the results are best read as early rather than settled.
- Best evidence:
Nicotinamide Riboside
Nicotinamide riboside is a form of vitamin B3 that cells convert into NAD+, a molecule central to energy production and to sirtuin proteins. People mostly look at it for healthy aging, since NAD+ levels decline over the years, but the evidence for that use is limited. One small trial in 58 people with COPD found that interleukin 8, an inflammation marker, went down, though that is a single study.
- Best evidence:
N-Phenylacetyl-L-prolylglycine ethyl ester
N-Phenylacetyl-L-prolylglycine ethyl ester, better known as Noopept, is a lab-made compound related to the brain's own peptides, and it is thought to influence how nerve cells signal and adapt. People mostly look at it for mild problems with memory and thinking, and one small trial of 41 people with mild cognitive impairment found that rehabilitation after brain injury improved, though the evidence is limited. That study compared it with piracetam and came from a single research group, so there is too little research to say how well the result holds up.
- Best evidence:
Octopamine
Octopamine is a trace amine, a compound chemically related to the stress messenger norepinephrine, made in small amounts in the body and found in some plants. People have looked at it mainly for urinary incontinence, and the evidence is moderate: in three trials, signs of incontinence improved. Those studies were small, with 97 participants in total, and tested norfenefrine, a close relative, in women with stress incontinence.
- Best evidence:
Oregano
Oregano is a culinary herb whose leaves and oil contain aromatic compounds, such as carvacrol and thymol, that plants use for their own defense. People mostly look at oregano oil for intestinal parasites, and the evidence is limited: in one study, gut parasites were reduced after emulsified oil. That study included only 13 people, so it is too small to show how well the result would hold up more broadly.
- Best evidence:
Palmitoylethanolamide
Palmitoylethanolamide, often called PEA, is a fatty compound your body makes naturally, where it helps calm irritated nerves and regulate inflammation and pain signaling. People have looked at it for menstrual cramps, but the one small trial reviewed here, with 67 participants, found no clear difference in pain compared with placebo. That evidence is very limited, so it says little about how PEA works for other kinds of pain or over longer periods.
- Best evidence:
Patchouli
Patchouli is a mint-family plant whose leaves yield an earthy essential oil, and its scent compounds are picked up by smell receptors linked to brain areas for mood and arousal. In a small trial of 43 adults, nervous system activity went down after inhaling patchouli fragrance, though the evidence is limited. That was a single study in healthy adults, so it says little about how patchouli affects felt stress.
- Best evidence:
Pea Protein
Pea protein is a protein powder made from yellow peas, and the body breaks it down into amino acids it uses to build and repair muscle and other tissues. People mostly look at it for cancer-related fatigue, and the evidence there is limited: one small trial of 39 participants found fatigue symptoms improved. Because that is a single small study, it is too early to say how well the result would hold up in other people.
- Best evidence:
Plantago Major Seeds
Plantago major seeds come from broadleaf plantain, a common weed, and contain mucilage, a gummy fiber that swells with water and adds bulk in the gut. People have long used them for bowel regularity, but the evidence is very limited, since no modern clinical trials on these seeds turned up. A mild bulk-forming effect is inferred from psyllium, a relative with similar fiber, so it remains an educated guess.
- Best evidence:
Purslane Extract
Purslane is a leafy succulent plant, and its extract is rich in omega-3 fats and antioxidant compounds that are thought to help calm inflammation in the body. People have mostly looked at it for rheumatoid arthritis, and in one small trial of 77 people, symptoms eased, though the evidence is limited. That is a single study, so it is too early to say how well the result would hold up in larger or longer trials.
- Best evidence:
Pygeum
Pygeum is an extract from the bark of the African plum tree, thought to calm inflammation in the prostate and urinary tract. People mostly look at it for urinary symptoms linked to an enlarged prostate, and the evidence is moderate: research found those symptoms eased. Still, the findings rest on one small study of 430 people, so it is hard to say how well the results hold up more broadly.
- Best evidence:
Sesamin
Sesamin is a natural compound found in sesame seeds, part of a family of plant substances called lignans that the body can absorb and process in the liver. People mostly look at it for blood pressure, and the one small study found that blood pressure improved in adults with high blood pressure, though the evidence is limited. That trial included only 25 people, so it is too early to say how well the result holds up in larger or more varied groups.
- Best evidence:
Shatavari
Shatavari is an Ayurvedic herb, the root of a plant called Asparagus racemosus, traditionally used to support reproductive health and the hormones involved in making breast milk. People mostly look at it for lactation, but the evidence is very limited: two small trials with 124 people found no clear difference in milk production. Because those studies were few and short on detail, they can't say whether it helps, and most of its reputation still rests on tradition.
- Best evidence:
Shirazi thyme
Shirazi thyme is a fragrant herb, known scientifically as Zataria multiflora, whose leaves are rich in aromatic compounds such as thymol and carvacrol that have antioxidant and antimicrobial activity. People mostly look at it for respiratory health, but the evidence is very limited: one analysis of 394 participants found no clear difference in cough. That is a small body of research, so it is too early to say whether the herb helps.
- Best evidence:
St. John's Wort
St. John's wort is a yellow-flowered herb whose extracts appear to act on brain chemistry, slowing the reuptake of messengers like serotonin, dopamine and norepinephrine so they stay active longer. Most people look at it for depression, and the evidence is strong: across three pooled analyses covering over 3,000 people, depression symptoms improved. Those results mainly concern mild to moderate depression, and the effect size was moderate rather than dramatic.
- Best evidence:
Torbangun
Torbangun is the leaf of Coleus amboinicus, an aromatic herb eaten in Batak cooking in Indonesia, where nursing mothers have traditionally relied on it. People look at it for breast milk production, and the evidence is limited: in one study, milk production went up. That study was small, with 67 participants, so it is too early to say how reliably it works or for whom.
- Best evidence:
Trehalose
Trehalose is a natural sugar made of two linked glucose molecules, found in mushrooms, yeast and some plants, where it helps cells withstand drying and oxidative stress. Most people look at it for dry eye, and the evidence is moderate: in two trials of eye drops, dry eye symptoms improved. Those studies were small, involving only 70 people in total, so the findings are early and say little about long-term use.
- Best evidence:
White Mulberry
White mulberry is a tree whose leaves and extracts contain plant compounds that can slow tyrosinase, an enzyme involved in making the skin pigment melanin. People mostly look at it for skin pigmentation, and in one trial of 50 people with melasma, a mulberry extract oil applied to the skin improved hyperpigmentation versus placebo. The evidence is limited, resting on one small study of a topical oil rather than mulberry taken by mouth.
- Best evidence:
Baby Formula
Baby formula is a manufactured food made to stand in for breast milk, giving infants the protein, fats, carbohydrates, vitamins and minerals they need to grow when breastfeeding isn't possible or is supplemented. Families usually look at it as a way to feed a baby, but little research on it has been reviewed here so far. Because of that, there are no findings to report yet, and questions about a particular baby's feeding are best taken to a pediatrician.
- Best evidence:
Supplements
Dietary supplements are concentrated forms of nutrients or plant compounds, such as vitamins, minerals, herbs, and amino acids, that add to what people get from food and can support processes like energy production, bone upkeep, and immune function. Little research on the category has been reviewed here so far. Evidence differs a lot from one supplement to the next, so results for one say little about another.
- Best evidence:
Calorie Blocker
Calorie blocker is a catch-all name for supplements marketed to limit how much fat or starch your body absorbs from a meal, usually by interfering with digestive enzymes or binding to food in the gut. People mostly look at these products for weight management, but little research on them has been reviewed here so far. Products sold under this label vary widely, so it is hard to say how well they work.
- Best evidence:
Emollients
Emollients are moisturizing creams, lotions and ointments that soften the skin and help it hold water by forming a thin layer that slows moisture loss from the surface. People mostly look at them for dry, rough or irritated skin, but little research on them has been reviewed here so far, so there are no findings to report yet. Until more studies are looked at, it's hard to say how well they work, for whom, or how one type compares with another.
- Best evidence:
Erythropoiesis-Stimulating Agents
Erythropoiesis-stimulating agents are substances that mimic erythropoietin, the hormone made mostly in the kidneys that signals bone marrow to produce more red blood cells. Little research on them has been reviewed here so far, so there are no trial findings to report yet. That makes it too early to say how well they work or for whom.
- Best evidence:
Fermented Foods
Fermented foods are foods like yogurt, kefir, sauerkraut, kimchi and miso, made when bacteria or yeasts break down sugars, and many carry live microbes that pass through the gut. People mostly look at them for digestion and gut health, but little research on them has been reviewed here so far. Because of that, it is too early to say how they compare with other foods or what benefits to expect.
- Best evidence:
Genetically Modified Organisms
Genetically modified organisms are plants, animals, or microbes whose DNA has been deliberately changed in a lab, often to add a trait such as pest resistance or a higher nutrient content in a crop. Little research on them has been reviewed here so far, so there are no findings to report yet. Because they are foods and ingredients rather than a typical supplement, any conclusions would depend heavily on which organism and which change are being discussed.
- Best evidence:
Guided Imagery
Guided imagery is a mind-body practice in which a recording or a person leads you to picture calm, vivid scenes, a mental focus that can shift the body's stress response toward relaxation. Little research on it has been reviewed here so far, so there are no findings to report yet. Until more studies are reviewed, how well it works remains an open question.
- Best evidence:
Insect Protein
Insect protein is a protein-rich powder made from ground crickets, mealworms or similar insects, and it supplies amino acids the body uses to build and repair muscle and other tissues. People mostly look at it as an alternative protein source, though little research on it has been reviewed here so far. Because of that, it is too early to say how it compares with more familiar proteins such as whey or soy.
- Best evidence:
Microbiota Accessible Carbohydrates
Microbiota accessible carbohydrates, often shortened to MACs, are the parts of plant foods, such as certain fibers and resistant starches, that escape digestion in the small intestine and reach the colon, where gut bacteria ferment them into compounds like short-chain fatty acids. People mostly look at them for gut and metabolic health, but little research on them has been reviewed here so far. Because of that, it is too early to say what they do for any particular outcome.
- Best evidence:
Motor Imagery
Motor imagery is the mental rehearsal of a movement without actually performing it, which activates many of the same brain regions that plan and control the real action. People mostly look at it to support skill learning and recovery of movement, but little research on it has been reviewed here so far. For now, it is best understood as a mental practice technique whose effects remain to be sorted out.
- Best evidence:
Mouthwash
Mouthwash is a liquid rinse swished around the mouth to freshen breath and lower the amount of bacteria and food debris sitting on the teeth, gums and tongue. Little research on it has been reviewed here so far, so there are no trial findings to report yet. Until that changes, it's best to think of it as a everyday oral-care product whose effects on health haven't been weighed up on this page.
- Best evidence:
Mycoprotein
Mycoprotein is a protein-rich food made by fermenting a fungus, and in the body it serves as a source of protein and fibre. Little research on it has been reviewed here so far, so there are no findings to report yet. For now, it is better understood as a food ingredient than as something with established effects.
- Best evidence:
Myofascial Release
Myofascial release is a hands-on bodywork technique in which a therapist applies slow, sustained pressure to the fascia, the connective tissue that wraps muscles, with the aim of easing tightness and restoring movement. People mostly look at it for muscle tension and soreness, but little research on it has been reviewed here so far, so there are no findings to report yet. Until that changes, anything said about how well it works would be guesswork rather than evidence.
- Best evidence:
Nondigestible Fermentable Carbohydrates
Nondigestible fermentable carbohydrates are plant fibers and similar sugars that pass through the small intestine intact and are fermented by bacteria in the colon, feeding those microbes and producing short-chain fatty acids the gut lining can use. Little research on them has been reviewed here so far, so there are no findings to report yet. Until more studies are covered, it is hard to say who might benefit or how large any effect could be.
- Best evidence:
Oral Immunotherapy
Oral immunotherapy is a approach in which a person with a food allergy eats tiny, carefully increasing amounts of the allergen so the immune system gradually becomes less reactive to it. People look at it mainly for food allergies, but little research on it has been reviewed here so far. That means it's too early to say much about how well it works or who it suits best.
- Best evidence:
Painting Therapy
Painting therapy is a form of creative art therapy in which people paint, often with a trained guide, to express feelings and engage attention, movement and imagination together. Little research on it has been reviewed here so far, so there are no trial findings to report yet. That means it's too early to say who might benefit, how much, or how it compares with other approaches.
- Best evidence:
Paraprobiotics
Paraprobiotics are inactivated, non-living microbial cells or their fragments, often heat-killed bacteria, that can still interact with immune cells and the lining of the gut. Little research on them has been reviewed here so far, so there are no findings to report yet. Because the picture is still taking shape, it is too early to say who might benefit or how large any effects could be.
- Best evidence:
Pet Ownership
Pet ownership means living with and caring for an animal such as a dog or cat, which can bring companionship and regular daily routines. Little research on it has been reviewed here so far, so there are no findings to report yet. It is too early to say what owning a pet might mean for health, and any answer will need careful studies.
- Best evidence:
Plant-Based Meats
Plant-based meats are FOOD PRODUCTS, not supplements. They are processed foods designed to mimic meat's taste and texture using plant proteins (soy, pea, wheat/seitan). Brands include Beyond Meat, Impossible Foods, and others. Nutritionally similar to meat in protein content but often higher in sodium and lower in some micronutrients. NO supplement outcomes - these are foods. Environmental benefits compared to meat. Ultra-processed, which some consider a health concern. Safe for most people; allergen considerations apply.
- Best evidence:
Postbiotics
Postbiotics are preparations of non-living microbes, or the substances those microbes produce, such as short-chain fatty acids and cell fragments, which may influence the gut lining and the immune system much as probiotics do. Little research on them has been reviewed here so far, so there are no findings to report yet. Because the evidence is so thin, it is too early to say who might benefit or what they might do.
- Best evidence:
Powdered Fruits and Vegetables
Powdered fruits and vegetables are dried, ground-up produce sold in scoops or capsules, and they supply some of the fiber, vitamins and plant compounds found in whole fruits and vegetables. People mostly look at them as a convenient way to add more produce to their day. Little research on them has been reviewed here so far, so there are no findings to report yet. Whole fruits and vegetables have a far larger body of research behind them.
- Best evidence:
Tazarotene
Tazarotene is a retinoid, a vitamin A-related compound that attaches to retinoic acid receptors in skin cells and helps steer how they grow and mature. Little research on it has been reviewed here so far, so there are no trial findings to report yet. It is used as a prescription medicine applied to the skin rather than a typical dietary supplement, so what holds for supplements may not carry over.
- Best evidence:
Thermal Spring Water
Thermal spring water is mineral-rich water that rises from deep underground, warmed by the earth and carrying dissolved minerals such as calcium, magnesium, sulfur compounds and bicarbonate, and it is traditionally used for bathing and drinking. Little research on it has been reviewed here so far, so there are no findings to report yet. Any benefits people describe are hard to separate from the effects of warm water, rest and the setting itself, and they likely vary with each spring's mineral makeup.
- Best evidence:
Wild Celery Extract
Wild celery extract comes from the seeds of the celery plant, which are rich in plant compounds such as phthalides and flavonoids that researchers have studied for their possible effects on blood vessels and inflammation. Little research on it has been reviewed here so far, so there are no trial findings to report yet. Until larger human studies are available, what it actually does for people remains an open question.