Condition
Hair Loss
Hair loss, or alopecia, is thinning or shedding of scalp hair, with causes ranging from genetics to nutrient shortfalls to medical conditions. Among supplements, the evidence is moderate for biotin, iron and zinc, all linked to hair loss when the body is low in them. Evidence is thinner elsewhere: two small trials of probiotics, with 219 people, found no clear difference in hair regrowth.
Sources: PMID 38966052; PMID 39275216
- Supplements studied
- 4
- Graded outcomes
- 2
- Trials
- 12
- People studied
- 2,132
Evidence by supplement
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Hair Regrowth Moderate Improvement | Improves (the measure goes up) | Moderate effect | 8 studies | 1,778 people | ||
Studies that measured hair regrowth
| ||||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Hair Regrowth No effect | NoneNo effect | 2 studies | 219 people | |||
Studies that measured hair regrowth | ||||||
| Microbiome | Improves (the measure goes up) | 115 people | ||||
Saw Palmetto
- Hair Regrowth: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Hair Regrowth | Improves (the measure goes up) | 1 study | 100 people | |||
Studies that measured hair regrowth | ||||||
Vitamin E
- Hair Regrowth: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Hair Regrowth | Improves (the measure goes up) | 1 study | 35 people | |||
Studies that measured hair regrowth | ||||||
Key findings
- Hair RegrowthImproves (the measure goes up)
The Hair Loss (Alopecia) Support protocol
2 primary supplements · 4 supporting supplements
Shop the evidence-backed picks
Fullscript collectionSkin: evidence-graded picksOpen on Fullscript
The collection holds the supplements we grade A or B for its theme, in third-party tested products where the catalog has them. It opens in our Fullscript store. You can look through it without signing in; Fullscript asks for a free account to order.
Or shop one supplement
The supplement graded A or B for Hair Loss. Each opens third-party tested products for that supplement.
- Grade A
We earn from purchases made in our Fullscript store, and links to Fullscript, iHerb or Thorne carry our referral, so we may earn a commission at no extra cost to you. Grades come from the research and never change based on what we earn. Full disclosure
Studies cited
100 studies from PubMed
- The effects of probiotic supplementation on cardiometabolic health in patients with prediabetes: a systematic review, meta-analysis, and GRADE assessment.
- Lactococcus lactis strain Plasma activates plasmacytoid dendritic cells and mitigates common cold-like symptoms in healthy adults: a meta-analysis of individual participant data.
- Probiotics and Immune Health: Current Knowledge and Future Perspectives
- Probiotics for Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis
- Probiotics for Prevention and Treatment of Diarrhea: A Systematic Review and Meta-Analysis
- Probiotics for the Prevention and Treatment of Depression: A Systematic Review and Meta-Analysis
- Effects of Probiotics on Metabolic Syndrome: A Systematic Review of Randomized Clinical Trials
- Probiotics and Weight Loss: A Systematic Review and Meta-Analysis
- The Gut Microbiome, Probiotics, and Their Impact on Skin Health: A Review
- Health Benefits of Probiotics: A Review
- Probiotics: Comprehensive Review of Growth Promotion Mechanisms and Action in Food Products
- Probiotics: Classification, Mode of Action and Role in Human Nutrition
- Safety of Probiotics: A Comprehensive Review
- Probiotics, Prebiotics and Inflammation: A Review of the Science
- Probiotics and Healthy Ageing: A Systematic Review and Meta-Analysis
- World Gastroenterology Organisation Global Guidelines: Probiotics and Prebiotics
- Probiotics for Human Use: Current Advances and Future Perspectives
- The effects of minoxidil, 1% pyrithione zinc and a combination of both on hair density: a randomized controlled trial
- An open, randomized, comparative study of oral finasteride and 5% topical minoxidil in male androgenetic alopecia
- Changes in hair weight and hair count in men with androgenetic alopecia, after application of 5% and 2% topical minoxidil, placebo, or no treatment
- A randomized, single-blind trial of 5% minoxidil foam once daily versus 2% minoxidil solution twice daily in the treatment of androgenetic alopecia in women
- A multicenter, randomized, placebo-controlled, double-blind clinical trial of a novel formulation of 5% minoxidil topical foam versus placebo in the treatment of androgenetic alopecia in men
- Randomized clinical trial comparing 5% and 1% topical minoxidil for the treatment of androgenetic alopecia in Japanese men
- A randomized, placebo-controlled trial of 5% and 2% topical minoxidil solutions in the treatment of female pattern hair loss
- A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in men
- Probiotics for people with cystic fibrosis.
- Probiotics for the prevention of gestational diabetes mellitus: A meta-analysis of randomized controlled trials.
- The effects of probiotics supplements on metabolic indices and clinical signs in patients with diabetic retinopathy, a randomized double blind clinical trial.
- Effect of applying Lactiplantibacillus plantarum subsp. plantarum N793 to the scalps of men and women with thinning hair: a randomized, double-blind, placebo-controlled, parallel-group study.
- Randomized Clinical Trial to Evaluate the Effect of Probiotic Intake on Androgenic Alopecia.
- Impact of probiotics on sleep quality and mood states in patients with insomnia: a systematic review and meta-analysis.
- Gaba-producing lactobacilli boost cognitive reactivity to negative mood without improving cognitive performance: A human Double-Blind Placebo-Controlled Cross-Over study.
- The effect of probiotic consumption on lipid profile, glycemic index, inflammatory markers, and liver function in NAFLD patients: A systematic review and meta-analysis of randomized controlled trials.
- Efficacy of probiotics in the treatment of oral mucositis in head and neck cancer patients: A systematic review and meta-analysis.
- The effect of probiotics on severe oral mucositis in cancer patients undergoing chemotherapy and/or radiotherapy: A meta-analysis.
- Oral probiotic supplementation to alleviate diarrhea induced by fluoropyrimidines or irinotecan-based chemotherapy: A systematic review and meta-analysis.
- The impact of probiotics on core autism symptoms - A systematic review and meta-analysis of randomized clinical trials.
- Efficacy and safety of Bacteroides fragilis BF839 for pediatric autism spectrum disorder: a randomized clinical trial.
- Probiotics for autism spectrum disorder: An updated systematic review and meta-analysis of effects on symptoms.
- The efficacy and safety of probiotics in the adjuvant treatment of psoriasis: a systematic review and meta-analysis of randomized controlled trials.
- Effects of probiotic supplementation on testosterone levels in healthy ageing men: A 12-week double-blind, placebo-controlled randomized clinical trial.
- A 12-Week, Single-Centre, Randomised, Double-Blind, Placebo-Controlled, Parallel-Design Clinical Trial for the Evaluation of the Efficacy and Safety of Lactiplantibacillus plantarum SKO-001 in Reducing Body Fat.
- Effects of oral supplementation of probiotics on body weight and visceral fat in obese patients: a meta-analysis and systematic review.
- The effects of probiotics administration during pregnancy on preeclampsia and associated maternal, fetal, and newborn outcomes: a systematic review and meta-analysis.
- Effects of probiotics supplementation on glycemic profile in adults with type 2 diabetes mellitus: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials.
- The Effect of Probiotics on Obesity with Comorbid Depression: A Systematic Review and Meta-Analysis.
- A network meta-analysis of probiotics in the treatment of childhood asthma.
- Efficacy of probiotics as adjuvant therapy in bronchial asthma: a systematic review and meta-analysis.
- Efficacy and safety of Saccharomyces boulardii as an adjuvant therapy for the eradication of Helicobacter pylori: a meta-analysis.
- Efficacy of probiotics regimens for Helicobacter pylori eradication: A systematic review, pairwise, and network meta-analysis of randomized controlled trials.
- Effect of probiotics on C-reactive protein levels in schizophrenia: Evidence from a systematic review and meta-analysis.
- Probiotics Supplementation for Improving Glucolipid Parameters in Individuals with Prediabetes: A Systematic Review and Meta-Analysis of Randomized Trials.
- Systematic review and meta-analysis on probiotics as treatment for food allergies among pediatric patients: A 2024 update.
- Efficacy of Oral Probiotic Supplementation in Preventing Vulvovaginal Infections During Pregnancy: A Randomized and Placebo-Controlled Clinical Trial.
- Clinical effects of probiotics on the treatment of gingivitis and periodontitis: a systematic review and meta-analysis.
- Evaluation of the efficacy of probiotics in the chemoradiotherapy of colorectal cancer: a meta-analysis of Randomized Controlled Trials.
- Clinical efficacy of probiotic supplementation in the treatment of knee osteoarthritis: a meta-analysis.
- The effect of probiotics on select cognitive domains in mild cognitive impairment and Alzheimer's disease: A systematic review and meta-analysis.
- Efficacy of probiotic supplementation in influencing cognitive function in Alzheimer's disease: A systematic review and meta-analysis.
- Effectiveness of probiotic supplements on cognitive function in mild cognitive impairment and Alzheimer's disease: A meta-analysis of randomized controlled trials.
- Probiotics are a good choice for the treatment of bacterial vaginosis: a meta-analysis of randomized controlled trial
- Efficacy and safety of Saccharomyces boulardii CNCM I-745 for the treatment of pediatric acute diarrhea in China: a systematic review and meta-analysis.
- Efficacy of probiotics in reducing the duration and severity of acute gastroenteritis in children: A meta-analysis of randomized controlled trials.
- Investigating the effects of probiotics during the menopause transition: A systematic review & meta-analysis.
- Effects of probiotic supplements on bone mineral density and bone turnover markers in postmenopausal women: A systematic review.
- Impact of probiotic supplementation on serum levels of brain-derived neurotrophic factor: GRADE-based dose-response meta-analysis.
- Probiotic Supplementation and Inflammatory Status in Coronary Artery Disease: A Systematic Review and Meta-Analysis.
- Serenoa repens monotherapy for benign prostatic hyperplasia (BPH): an updated Cochrane systematic review
- Serenoa repens extract for benign prostate hyperplasia: a randomized controlled trial
- Observational database serenoa repens (DOSSER): overview, analysis and results. A multicentric SIUrO (Italian Society of Oncological Urology) project
- Saw palmetto for benign prostatic hyperplasia
- Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms: a randomized trial
- Improving BPH symptoms and sexual dysfunctions with a saw palmetto preparation? Results from a pilot trial
- Comparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year study
- Comparison of finasteride (Proscar) and Serenoa repens (Permixon) in the inhibition of 5-alpha reductase in healthy male volunteers
- The effect of increasing doses of saw palmetto fruit extract on serum prostate specific antigen: analysis of the CAMUS randomized trial
- Randomized, double-blind, placebo-controlled trial of saw palmetto in men with lower urinary tract symptoms
- The Effect of Dietary Supplements on Male Infertility in Terms of Pregnancy, Live Birth, and Sperm Parameters: A Systematic Review and Meta-Analysis.
- Clinical effectiveness of vitamin E and vitamin B6 for improving pain severity in cyclic mastalgia
- Evaluating the effects of vitamin D and vitamin E supplement on premenstrual syndrome: A randomized, double-blind, controlled trial
- Daily supplementation of tocotrienol-rich fraction or alpha-tocopherol did not induce immunomodulatory changes in healthy human volunteers
- Effects of supplementation with tocotrienol-rich fraction on immune response to tetanus toxoid immunization in normal healthy volunteers
- Effect of 50- and 100-mg vitamin E supplements on cellular immune function in noninstitutionalized elderly persons
- Vitamin E supplementation enhances cell-mediated immunity in healthy elderly subjects
- Vitamin E supplementation and in vivo immune response in healthy elderly subjects. A randomized controlled trial
- Effects of gamma-tocopherol supplementation on thrombotic risk factors
- Aspirin prevents stroke but not MI in women; vitamin E has no effect on CV disease or cancer
- Effects of vitamin E on stroke: a systematic review with meta-analysis and trial sequential analysis.
- Effects of vitamin E on stroke subtypes: meta-analysis of randomised controlled trials.
- The effect of vitamin E on endothelial function of micro- and macrocirculation and left ventricular function in type 1 and type 2 diabetic patients
- The relationship between dose of vitamin E and suppression of oxidative stress in humans
- Effects of vitamin E on lipid peroxidation in healthy persons
- Dose dependent elevation of plasma tocotrienol levels and its effect on arterial compliance, plasma total antioxidant status, and lipid profile in healthy humans supplemented with tocotrienol rich vitamin E
- Assessment of the safety of supplementation with different amounts of vitamin E in healthy older adults
- Assessment of the safety of high-dose, short-term supplementation with vitamin E in healthy older adults
- Effect of oral vitamin E (alpha-tocopherol) supplementation on vascular endothelial function in Type 2 diabetes mellitus
- Vitamin E in the primary prevention of cardiovascular disease and cancer: the Women's Health Study: a randomized controlled trial
- Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)
- Prostate cancer and supplementation with alpha-tocopherol and beta-carotene: incidence and mortality in a controlled trial
- Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)