Vitamins & Supplements · Vitamin
Vitamin B7 (biotin)
Biotin (vitamin B7) · also called Biotin, vitamin B7
Biotin is a B vitamin your body needs to make fatty acids and use food. A true shortage is rare and shows as rashes, hair loss and brittle nails. Supplements are popular for hair and nails, but evidence in healthy people is thin. The key caution is that biotin can make blood tests, including heart tests, read wrongly.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Vitamin B7 (biotin)
Biotin (vitamin B7) is a water-soluble B vitamin found in many foods. It is needed to make fatty acids and to use food for energy. It is a nutrient, not a proven remedy: the clearest benefit is in people who are truly short of it, and the clearest risk is wrong results on some blood tests.
What it is
Biotin is a B vitamin. MedlinePlus says it is found in cereal, chocolate, egg yolk, legumes, milk, nuts, organ meats such as liver and kidney, pork and yeast. Amounts per portion were not available to us because the NIH fact sheet was blocked.
MedlinePlus gives an Adequate Intake of 30 mcg a day for adults 19 and older, including pregnant women, and 35 mcg for breastfeeding women; for babies and children 5 to 25 mcg by age. These are reference levels, not advice. Food and pills differ: the studies on hair, MS and diabetes used supplements.
Deficiency
A true lack of biotin is rare. MedlinePlus lists muscle pain, dermatitis, a swollen tongue, skin rashes, hair loss and brittle nails as signs. A review says frank symptomatic deficiency is rare.
Adults on long-term seizure medicines passed more biotin breakdown products in a 1997 study, which the authors took to mean probably lower biotin status. Small studies also suggest a marginal shortage in many pregnant women, based on markers that are hard to read; the birth defect finding is from mice.
Inherited biotinidase deficiency is a rare disorder in which the body cannot recycle biotin. Treated early, children develop normally; untreated it can cause seizures, low muscle tone, hair loss and skin rash.
What the research shows
Hair: the 2017 review found 18 reported cases, all in people with an underlying cause, all improved. The authors found no sufficient evidence for supplements in healthy people. Nails: reviews say trials showed firmer, harder, thicker brittle nails, but the studies are small.
Multiple sclerosis: a first trial of 154 people found 12.6% improved on biotin versus none on placebo. The larger trial of 642 people found 12% versus 9%, not significant, and its authors did not recommend it. Both used pharmaceutical-grade biotin at 300 mg a day.
Type 2 diabetes: 5 small trials gave total cholesterol 0.22 mmol/L lower, but glucose and triglyceride ranges include no effect.
At a glance
Traditional uses history, not proof
- Part of ordinary diets as a B vitamin
- A popular use for hair, skin and nails is modern marketing, not proof of benefit
Studied for research
- Everyday need and deficiency signs, high certainty
- Inherited biotinidase deficiency, moderate certainty (expert review)
- Brittle nails, low certainty
- Hair in healthy people, insufficient evidence
- Progressive MS at very high doses, evidence against
- Type 2 diabetes markers and pregnancy status, very low certainty
Main compounds
- Biotin (D-biotin), PubChem CID 171548
Common forms
- Biotin from food (cereal, egg yolk, legumes, milk, nuts, organ meats, pork, yeast)
- Biotin supplements, amounts vary by product and are not covered
- Pharmaceutical-grade high-dose biotin (MD1003) used only in MS trials
Research links: 2017 review: biotin for hair loss · 2017 study: biotin and lab test accuracy (JAMA) · 2020 trial: high-dose biotin in progressive MS · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Biotin (vitamin B7)
- Common names
- Biotin (English); Vitamin B7 (English)
- Family or group
- B vitamins (water-soluble)
- Harvest and processing
- Not covered.
- Look-alikes and adulterants
- Name: Pantothenic acid (vitamin B5); Note: MedlinePlus covers it on the same page, but it is a different vitamin with its own page.
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Biotin (D-biotin) PubChem 171548 | B vitamin | Food amounts per portion not read (NIH fact sheet blocked) | Helps enzymes that make fatty acids and process fats, proteins and carbohydrates (MedlinePlus). 12 6 | Human data |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Biotin-dependent carboxylase enzymes | Not specified in the sources read | Biotin is required for enzymes that make fatty acids and break down fats, proteins and carbohydrates. Without enough biotin, an enzyme-linked marker (urinary 3-hydroxyisovaleric acid) rises. 12 6 4 | Human data |
| Streptavidin-biotin lab tests | Not applicable | Many immunoassays use biotin-streptavidin binding; excess biotin in the sample can disrupt this and give falsely high or low results. 2 11 | Human data |
| Energy supply of nerve cells (hypothesis) | Not specified | The SPI2 authors say high-dose biotin might enhance neuron energetics; the trial did not confirm benefit. 1 | Human data |
Absorption, metabolism and elimination
- Absorption
- Not found in the sources read.
- Distribution
- Not found.
- Metabolism
- Adults on anticonvulsants passed more biotin breakdown products, suggesting faster breakdown (observational).
- Elimination
- Not found.
- Bioavailability
- Not found. Food-bound biotin versus free supplements was not read.
Isolated compounds versus whole extracts
Deficiency signs and the inherited-disorder results concern biotin in the diet or free biotin treatment. The MS, diabetes and lab-test findings are for supplements, some at very high amounts. Food sources and pills differ.
Nutritional composition
MedlinePlus names cereal, chocolate, egg yolk, legumes, milk, nuts, organ meats, pork and yeast as foods with biotin. Amounts per portion were not available because the NIH fact sheet was blocked.
1 high certainty1 moderate certainty1 low certainty2 very low certainty1 not enough evidence1 evidence against
What was looked at
The 7 benefits and uses checked for Vitamin B7 (biotin), each with how strong the evidence is. Tap one to open it.
- Everyday need and deficiency signsHigh certainty
- Inherited biotinidase deficiency (a rare condition)Moderate certainty
- Brittle nailsLow certainty
- Hair growth and hair lossNot enough evidence
- Progressive multiple sclerosis (very high doses)Evidence against
- Blood sugar and blood fats in type 2 diabetesVery low certainty
- Biotin status in pregnancyVery low certainty
Lab markers tracked in the studies
Urinary 3-hydroxyisovaleric acidNail firmness, hardness and thicknessDisability score (EDSS) and walking time in MSFasting blood glucoseTotal cholesterol and triglyceridesBiotin-dependent enzyme activity (PCC) in blood cells
What is Vitamin B7 (biotin) good for?
The main studied uses and how strong the human evidence is for each. Many results are for very high doses or for people with a specific condition, not for ordinary food intake.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Everyday need and deficiency signs
High certaintyBiotin is an essential vitamin. The body needs it to make fatty acids and to use food. True lack is rare, and it shows as skin rashes, hair loss, brittle nails, muscle pain, dermatitis or a swollen tongue.
2 studiesDietary biotin from food. Supplements are a separate question, covere…
Studies, doses and limits
What the trials found
MedlinePlus lists skin rashes, hair loss and brittle nails as signs of deficiency and says there are no known toxic symptoms from biotin. A 2017 review says frank symptomatic deficiency is rare.
Results
Biotin is needed, and a true shortage causes skin, hair and nail changes plus muscle pain. A shortage is uncommon.
Effect sizes as reported
MedlinePlus Adequate Intake (a reference level, not advice): 30 mcg a day for adults 19 and older, including pregnant women; 35 mcg for breastfeeding women; 5 to 25 mcg for babies and children by age.
Why this rating
High that biotin is an essential nutrient and that deficiency has these signs, based on the reference page and review; this is not a trial result.
Form and dose studied
Dietary biotin from food. Supplements are a separate question, covered under the other benefits.
Who was studied
General population; deficiency risk groups are not defined by the sources read except pregnancy and anticonvulsant use (see below and Safety).
Limits
Descriptive sources, not trials. The NIH fact sheet could not be read (blocked), so food amounts per portion are not given.
Why researchers looked
Biotin is a B vitamin, so the first question is what happens without enough of it.
Traditional use
Biotin is part of ordinary diets. Its use as a supplement for hair, skin and nails is a modern marketing idea, and a popular use is not proof of benefit.
Proposed mechanism Authoritative guidance
Biotin works as a helper for enzymes that break down fats, proteins and carbohydrates and that make fatty acids. This is the standard textbook description given by MedlinePlus; it is not a finding from a trial.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab for lab-test errors, which matter even if you are not deficient.
Inherited biotinidase deficiency (a rare condition)
Moderate certaintyIn this rare inherited disorder the body cannot recycle biotin. Treated early with free biotin, children develop normally. This is a medical treatment under specialist care, not a general supplement use.
1 studiesOral free biotin, chosen by a specialist.
Studies, doses and limits
What the trials found
The GeneReviews expert review says people diagnosed before symptoms, for example by newborn screening, and treated with biotin have normal development, and that treatment is lifelong. It is not a randomised trial.
Results
Symptoms of untreated disease include seizures, low muscle tone, optic atrophy, hair loss and skin rash. Some problems already present, such as optic atrophy, hearing loss and developmental delay, may only partly reverse.
Why this rating
Moderate: clear and consistent expert description of a rare disorder, but not from randomised trials.
Form and dose studied
Oral free biotin, chosen by a specialist.
Who was studied
Babies, children and adults with the inherited disorder.
Limits
Applies only to the inherited disorder. It does not show that extra biotin helps people who are not deficient.
Why researchers looked
It is the clearest case where extra biotin changes the course of a condition.
Traditional use
Biotin is part of ordinary diets. Its use as a supplement for hair, skin and nails is a modern marketing idea, and a popular use is not proof of benefit.
Proposed mechanism Authoritative guidance
The body cannot recycle biotin, so its biotin-dependent enzymes lack the vitamin. Biotin replaces what is missing.
A proposed mechanism does not show that the effect happens in people.
Never treat suspected seizures or developmental problems with supplements at home; see a doctor.
Brittle nails
Low certaintySome trials found that taking biotin made brittle nails firmer, harder and thicker. The research is small and the review authors ask for larger controlled trials.
2 studiesOral biotin supplements; amounts differ by study and are not summaris…
Studies, doses and limits
What the trials found
A 2018 review says clinical trials showed improvement in firmness, hardness and thickness of brittle nails with oral biotin, and case reports suggest benefit in other nail conditions. It does not give trial sizes in the abstract. A 2017 review found 18 reported cases of biotin for hair or nail problems, all in people with a cause for the problem, all improved.
Results
Possible benefit for brittle nails, with weak controls and small numbers.
Effect sizes as reported
No pooled numbers in the abstracts.
Why this rating
Low: small and mostly uncontrolled studies, summarised in narrative reviews that do not give sizes.
Form and dose studied
Oral biotin supplements; amounts differ by study and are not summarised here.
Who was studied
Adults with brittle nails or other nail conditions.
Limits
Small studies; no pooled analysis; the larger trials the authors ask for were not found. Not a test of biotin from food.
Why researchers looked
Brittle nails are one of the signs of biotin deficiency, so biotin has been tried for brittle nails in people who are not clearly deficient.
Traditional use
Biotin is part of ordinary diets. Its use as a supplement for hair, skin and nails is a modern marketing idea, and a popular use is not proof of benefit.
Proposed mechanism Review summary
Not shown. The review authors describe the pharmacology but do not report a tested mechanism in the abstract.
A proposed mechanism does not show that the effect happens in people.
Biotin supplements can distort blood test results; see Safety.
Hair growth and hair loss
Not enough evidenceIn people with healthy hair, there is not enough evidence that biotin supplements help. Reported benefit is in people with a cause such as deficiency or uncombable hair.
1 studiesOral biotin supplements.
Studies, doses and limits
What the trials found
A 2017 systematic review found 18 reported cases of biotin for hair or nail changes. In every case the person had an underlying reason for poor hair or nail growth, and all improved. The authors found limited research in healthy people and proposed there is a lack of sufficient evidence for supplementation in healthy individuals.
Results
No benefit shown for healthy people. Possible help where a deficiency or specific hair condition exists.
Effect sizes as reported
18 cases improved; no controlled trial numbers in the abstract.
Why this rating
Insufficient for healthy people. Case reports in people with a cause are low-quality evidence.
Form and dose studied
Oral biotin supplements.
Who was studied
Adults with hair loss from deficiency or uncombable hair syndrome (reported cases).
Limits
Cases cannot show cause. Hair loss has many causes, and a doctor can look for them.
Why researchers looked
Hair loss is a sign of deficiency, and biotin is widely sold for hair.
Traditional use
Biotin is part of ordinary diets. Its use as a supplement for hair, skin and nails is a modern marketing idea, and a popular use is not proof of benefit.
Proposed mechanism Review summary
Not shown for healthy hair.
A proposed mechanism does not show that the effect happens in people.
See Safety for lab-test interference before blood tests for hair loss.
Progressive multiple sclerosis (very high doses)
Evidence againstTwo trials tested pharmaceutical-grade biotin at about 10,000 times the usual adequate intake. The small first trial was positive; the larger second trial (642 people) found no significant benefit. Not recommended for MS by its authors.
2 studiesPharmaceutical-grade MD1003 at 100 mg three times a day. Not the same…
Studies, doses and limits
What the trials found
The first trial (154 people, 12 months) found 12.6% on biotin improved on disability versus none on placebo (p = 0.005). The larger SPI2 trial (642 people) found 12% versus 9%, not significant (odds ratio 1.35, 95% CI 0.81 to 2.26). The authors concluded it cannot be recommended, and noted wrong results on some lab tests.
Results
Against use as an MS treatment; the earlier benefit was not confirmed.
Effect sizes as reported
Trial 1: 12.6% vs 0%. SPI2: 12% vs 9%, OR 1.35 (0.81 to 2.26).
Why this rating
The larger, later and better-powered trial found no significant benefit. SPI2 was funded by the product maker.
Form and dose studied
Pharmaceutical-grade MD1003 at 100 mg three times a day. Not the same as ordinary supplements or food biotin.
Who was studied
Adults with primary or secondary progressive MS.
Limits
Very high doses; the finding says nothing about food biotin or normal supplement amounts.
Why researchers looked
Biotin was tested as a possible way to support the energy of nerve cells in progressive MS.
Traditional use
Biotin is part of ordinary diets. Its use as a supplement for hair, skin and nails is a modern marketing idea, and a popular use is not proof of benefit.
Proposed mechanism Hypothesis
Authors suggested high-dose biotin might improve neuron and oligodendrocyte energy, which is a hypothesis.
A proposed mechanism does not show that the effect happens in people.
High doses distorted blood tests in the trial; see Safety.
Blood sugar and blood fats in type 2 diabetes
Very low certaintyA pooled analysis of 5 small trials found lower total cholesterol and a possible fall in glucose and triglycerides, but the ranges for glucose and triglycerides include no effect. Evidence is very weak.
1 studiesBiotin supplements; amounts not given in the abstract.
Studies, doses and limits
What the trials found
A 2022 meta-analysis of 5 randomised trials (445 people, 28 to 90 days) found fasting glucose 1.21 mmol/L lower (95% CI -2.73 to 0.31), total cholesterol 0.22 mmol/L lower (-0.25 to -0.19) and triglycerides 0.59 mmol/L lower (-1.21 to 0.03). Insulin showed no significant effect. HbA1c, LDL and HDL were too limited to conclude.
Results
A possible small effect on total cholesterol; glucose and triglyceride results could be chance.
Effect sizes as reported
FBG -1.21 mmol/L; TC -0.22; TG -0.59; insulin not significant.
Why this rating
Very low: only five short, small trials; two of three headline ranges include zero; no control for diet.
Form and dose studied
Biotin supplements; amounts not given in the abstract.
Who was studied
Adults with type 2 diabetes.
Limits
Short trials; no outcomes such as heart disease. Not a test of biotin from food.
Why researchers looked
Biotin takes part in sugar and fat metabolism, so researchers tested it in type 2 diabetes.
Traditional use
Biotin is part of ordinary diets. Its use as a supplement for hair, skin and nails is a modern marketing idea, and a popular use is not proof of benefit.
Proposed mechanism Review summary
Not shown in the abstract.
A proposed mechanism does not show that the effect happens in people.
People with diabetes should discuss supplements with their doctor and tell the lab about biotin.
Biotin status in pregnancy
Very low certaintySome small studies suggest many pregnant women have a marginal shortage of biotin. In mice this level of shortage caused birth defects. No study shows that biotin supplements prevent birth defects in people.
2 studiesBiotin supplements in the pilot (amounts not given in the abstract).
Studies, doses and limits
What the trials found
A 2009 review reports a pilot study in which biotin-dependent enzyme activity was low in 18 of 22 pregnant women, and in 4 of 4 with low activity, biotin supplements raised it by a mean of 95%. A 2017 review says marginal deficiency occurs in a substantial proportion of women and might raise birth-defect risk.
Results
A shortage marker is common in small studies; whether it harms babies in people is not shown.
Effect sizes as reported
18 of 22 low; mean +95% after biotin in 4 of 4.
Why this rating
Very low: small marker studies in women; the harm signal is from mice; markers are hard to interpret in pregnancy.
Form and dose studied
Biotin supplements in the pilot (amounts not given in the abstract).
Who was studied
Pregnant women.
Limits
Not a trial of birth outcomes.
Why researchers looked
Pregnancy raises the body's turnover of biotin, and mice with low biotin had offspring with defects.
Traditional use
Biotin is part of ordinary diets. Its use as a supplement for hair, skin and nails is a modern marketing idea, and a popular use is not proof of benefit.
Proposed mechanism Animal lab
Mouse studies show a marginal deficiency in the mother produces a more severe deficiency in the fetus.
A proposed mechanism does not show that the effect happens in people.
Ask your midwife or doctor about prenatal supplements; do not add large amounts on your own.
Connections to the rest of health
How Vitamin B7 (biotin) connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Preventive Wellness | High certainty | Everyday need and deficiency signs: Biotin is an essential vitamin. The body needs it to make fatty acids and to use food. True lack is rare, and it shows as skin rashes, hair loss, brittle nails, muscle pain, dermatitis or a swollen tongue. | 12 6 | |
| Balanced Nutrition | High certainty | Everyday need and deficiency signs: Biotin is an essential vitamin. The body needs it to make fatty acids and to use food. True lack is rare, and it shows as skin rashes, hair loss, brittle nails, muscle pain, dermatitis or a swollen tongue. | 12 6 | |
| Preventive Wellness | Moderate certainty | Inherited biotinidase deficiency (a rare condition): In this rare inherited disorder the body cannot recycle biotin. Treated early with free biotin, children develop normally. This is a medical treatment under specialist care, not a general supplement use. | 9 | |
| Hair Support | Low certainty | Brittle nails: Some trials found that taking biotin made brittle nails firmer, harder and thicker. The research is small and the review authors ask for larger controlled trials. Hair growth and hair loss: In people with healthy hair, there is not enough evidence that biotin supplements help. Reported benefit is in people with a cause such as deficiency or uncombable hair. | 3 7 | |
| Healthy Skin | Low certainty | Brittle nails: Some trials found that taking biotin made brittle nails firmer, harder and thicker. The research is small and the review authors ask for larger controlled trials. | 3 7 | |
| Brain Health | Evidence against | Progressive multiple sclerosis (very high doses): Two trials tested pharmaceutical-grade biotin at about 10,000 times the usual adequate intake. The small first trial was positive; the larger second trial (642 people) found no significant benefit. Not recommended for MS by its authors. | 1 8 | |
| Blood Sugar Balance | Very low certainty | Blood sugar and blood fats in type 2 diabetes: A pooled analysis of 5 small trials found lower total cholesterol and a possible fall in glucose and triglycerides, but the ranges for glucose and triglycerides include no effect. Evidence is very weak. | 10 | |
| Cholesterol Balance | Very low certainty | Blood sugar and blood fats in type 2 diabetes: A pooled analysis of 5 small trials found lower total cholesterol and a possible fall in glucose and triglycerides, but the ranges for glucose and triglycerides include no effect. Evidence is very weak. | 10 | |
| Pregnancy Support | Very low certainty | Biotin status in pregnancy: Some small studies suggest many pregnant women have a marginal shortage of biotin. In mice this level of shortage caused birth defects. No study shows that biotin supplements prevent birth defects in people. | 5 6 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Nutrition | Biological association | High certainty | Studied for: Everyday need and deficiency signs | 12 6 |
| Metabolism | Biological association | High certainty | Studied for: Everyday need and deficiency signs Studied for: Inherited biotinidase deficiency (a rare condition) | 12 6 9 |
| Nervous System | Biological association | Moderate certainty | Studied for: Inherited biotinidase deficiency (a rare condition) Studied for: Progressive multiple sclerosis (very high doses) | 9 1 8 |
| Integumentary System | Biological association | Low certainty | Studied for: Brittle nails Studied for: Hair growth and hair loss | 3 7 |
| Skin Hair Beauty | Biological association | Low certainty | Studied for: Brittle nails Studied for: Hair growth and hair loss | 3 7 |
| Metabolic System | Biological association | Very low certainty | Studied for: Blood sugar and blood fats in type 2 diabetes | 10 |
| Endocrine System | Biological association | Very low certainty | Studied for: Blood sugar and blood fats in type 2 diabetes | 10 |
| Reproductive System | Biological association | Very low certainty | Studied for: Biotin status in pregnancy | 5 6 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Biotin interference with laboratory tests | Adverse effect or risk | Documented risk | Biotin can make some blood tests read falsely high or low. Preparation or compound: Biotin supplements |
11 2 |
| Biotinidase deficiency | Clinically supported | Lifelong biotin treatment is standard for this inherited disorder. Preparation or compound: Free biotin |
9 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Urinary 3-hydroxyisovaleric acid | Biological association | Low certainty | Measured in trials: raised in marginal biotin deficiency and in anticonvulsant users. A lab change is not the same as a health benefit. | 4 5 |
| Nail firmness, hardness and thickness | Biological association | Low certainty | Measured in trials: improved with oral biotin in some studies. A lab change is not the same as a health benefit. | 3 |
| Disability score (EDSS) and walking time in MS | Biological association | Evidence against | Measured in trials: no significant improvement in the larger trial. A lab change is not the same as a health benefit. | 8 1 |
| Fasting blood glucose | Biological association | Very low certainty | Measured in trials: lower in the pooled estimate, but the range includes no change. A lab change is not the same as a health benefit. | 10 |
| Total cholesterol and triglycerides | Biological association | Very low certainty | Measured in trials: lower in the pooled estimate for total cholesterol; triglyceride range includes no change. A lab change is not the same as a health benefit. | 10 |
| Biotin-dependent enzyme activity (PCC) in blood cells | Biological association | Very low certainty | Measured in trials: low in many pregnant women; raised after biotin in a pilot. A lab change is not the same as a health benefit. | 5 |
J. Genes, receptors and enzymes
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| BTD (biotinidase) | Preliminary mechanism | Human | The inherited biotinidase deficiency is named from the enzyme that recycles biotin; the GeneReviews summary refers to BTD testing. | 9 |
L. Active compounds
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).
Evidence at a glance: what the research found for 7 outcomes
Each outcome below is one thing researchers measured. Certainty is how far the evidence can be trusted, not how well it works. The full studies are on the next tab.
The evidence
The research centre for Vitamin B7 (biotin). Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our existing biotin summary, read MedlinePlus and the FDA troponin page, and re-read PubMed abstracts for each study cited. Only abstracts were read for studies. Items we could not verify are flagged in the research gaps.
Study library: every study we checked 13
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Cree 2020 Safety and efficacy of MD1003 (high-dose biotin) in patients with progressive multiple sclerosis (SPI2): a randomised, double-blind, placebo-controlled, phase 3 trial Lancet Neurol · PMID 33222767 · DOI |
Randomised controlled trial |
642 Adults aged 18 to 65 with primary or secondary progressive multiple sclerosis, from 90 clinics in 13 countries. |
MD1003, pharmaceutical-grade oral biotin 100 mg three times a day (300 mg a day in total, about 10,000 times the adequate intake for adults in MedlinePlus) Mean 20.1 months in the placebo-controlled phase · vs Placebo |
Improvement: 39 of 326 (12%) on biotin versus 29 of 316 (9%) on placebo, not a significant difference. Adverse events: 84% vs 85%; serious events 26% vs 26%. One death in the biotin group, none on placebo. Biotin led to inaccurate results on lab tests that use biotinylated antibodies despite mitigation. The authors conclude it cannot be recommended for progressive MS. Odds ratio 1.35 (95% CI 0.81 to 2.26) Methods, limits and fundingOutcomes: Share improving on disability score (EDSS) or walking time at month 12, confirmed at month 15; safety Limitations: Pharmaceutical-grade product at a very high dose; the result does not apply to ordinary supplements or to food. Funding and conflicts: Funded by MedDay Pharmaceuticals, the maker of MD1003. Registration: NCT02936037 Read: abstract |
| Li 2017 Association of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults JAMA · PMID 28973622 · DOI |
Non randomised crossover trial |
6 6 healthy adults (2 women, 4 men, mean age 38) at an academic medical centre. |
Oral biotin supplement 10 mg a day (about 333 times the adequate intake for adults in MedlinePlus), a dose the authors call common in over-the-counter supplements 7 days, with a re-test 7 days after stopping · vs Each person was compared with their own baseline; 14 assays without biotin-streptavidin parts were the negative controls |
Interference was found in 9 of 23 (39%) assays that use biotin, and in none of the 14 assays that do not. Biotin competitive assays read falsely high in 5 of 8 (63%), and sandwich assays read falsely low in 4 of 15 (27%). 9/23 (39%) biotin assays affected vs 0/14 controls, P = .007 (Not reported in the abstract) Methods, limits and fundingOutcomes: 37 immunoassays for 11 blood analytes (thyroid hormones, PTH, prolactin, NT-proBNP, 25-hydroxyvitamin D, PSA, ferritin) Limitations: Very small preliminary study, not randomised. Which tests are affected depends on the test maker and machine. Funding and conflicts: Funding is not stated in the abstract. Registration: NCT03034707 Read: abstract |
| Lipner 2018 Biotin for the treatment of nail disease: what is the evidence? J Dermatolog Treat · PMID 29057689 · DOI |
Narrative review |
Published clinical trials and case reports of oral biotin for nail conditions. | Oral biotin |
Clinical trials showed improvement in firmness, hardness and thickness of brittle nails with oral biotin. Case reports and series suggest it may help some other nail conditions. The authors say larger controlled trials are needed to judge efficacy and dosing. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Nail firmness, hardness and thickness Limitations: Narrative review. Several of the studies it covers are small or uncontrolled, and the abstract does not give sizes. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Mock 1997 Biotin catabolism is accelerated in adults receiving long-term therapy with anticonvulsants Neurology · PMID 9371938 · DOI |
Observational comparison |
Adults on long-term anticonvulsant (seizure medicine) treatment, compared with others; the abstract gives no numbers. | None (medicine exposure); biotin status measured |
Adults on anticonvulsants passed more biotin breakdown products and more 3-hydroxyisovaleric acid. The authors concluded these medicines increased biotin breakdown and probably reduced biotin status. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Urinary biotin breakdown products and 3-hydroxyisovaleric acid, markers of biotin status Limitations: Small 1997 study; the abstract does not name the medicines or give group sizes. A lower biotin status was inferred from markers, not shown as a disease. Funding and conflicts: Research support from the US Public Health Service is listed in the record. Read: abstract |
| Mock 2009 Marginal biotin deficiency is common in normal human pregnancy and is highly teratogenic in mice J Nutr · PMID 19056637 · DOI |
Narrative review |
Review of studies of biotin status in pregnant women (urine marker and lymphocyte enzyme activity) and of mice. | Biotin status; biotin supplementation in 4 women |
About half of pregnant women passed more 3-hydroxyisovaleric acid, though the author notes pregnancy changes kidney function so this marker is hard to read. In a pilot study, enzyme activity was low in 18 of 22 pregnant women; in 4 of 4 with low activity, biotin supplements raised it by a mean of 95%. In mice, a matching degree of deficiency caused birth defects. The author says this raises concern that biotin deficiency may cause birth defects in people. 18 of 22 low; mean +95% in 4 of 4 after biotin (Not applicable) Methods, limits and fundingOutcomes: Urinary 3-hydroxyisovaleric acid, propionyl-CoA carboxylase activity Limitations: Marker-based, small pilot data in women; the birth-defect finding is from mice only. No study shows biotin supplements prevent birth defects in people. Funding and conflicts: Research support from the US National Institutes of Health (extramural) is listed in the record. Read: abstract |
| Mock 2017 Biotin: From Nutrition to Therapeutics J Nutr · PMID 28701385 · DOI |
Narrative review |
Review of biotin status testing, pregnancy, gene expression, large-dose biotin for multiple sclerosis and lab-test errors. | Biotin from diet and supplements |
Frank symptomatic biotin deficiency is rare. Some evidence suggests marginal biotin deficiency occurs in a substantial share of women during normal pregnancy and might raise the risk of birth defects. The review ends with reports of potentially dangerous wrong results on hormone blood tests in people who consume large amounts of biotin. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Biotin deficiency, pregnancy status, MS therapy, lab-test errors Limitations: Narrative review by one author. The pregnancy concern rests on small studies and on mice. Funding and conflicts: Research support from the US National Institutes of Health (extramural) is listed in the record. Read: abstract |
| Patel 2017 A Review of the Use of Biotin for Hair Loss Skin Appendage Disord · PMID 28879195 · DOI |
Systematic review |
Published case reports and randomised trials of biotin for hair and nail problems; the abstract reports 18 cases. | Oral biotin supplements, as reported in cases |
All 18 reported cases had an underlying cause of poor hair or nail growth, and all improved after biotin. The authors found limited research for healthy people and no sufficient evidence for supplements in healthy individuals. 18 reported cases, all improved; no trial numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Hair and nail growth Limitations: Mostly case reports, which cannot show cause. No controlled trial of healthy people was found by the authors. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Tourbah 2016 MD1003 (high-dose biotin) for the treatment of progressive multiple sclerosis: A randomised, double-blind, placebo-controlled study Mult Scler · PMID 27589059 · DOI |
Randomised controlled trial |
154 Adults with progressive multiple sclerosis (baseline EDSS 4.5 to 7) with worsening in the previous 2 years. |
MD1003, high-dose pharmaceutical-grade biotin 100 mg three times a day 12 months, then all patients took MD1003 for 12 more months · vs Placebo |
13 (12.6%) of the MD1003 group reached the primary endpoint versus none on placebo (p = 0.005). Safety was similar to placebo. 12.6% vs 0%, p = 0.005 (Not reported in the abstract) Methods, limits and fundingOutcomes: Disability reversal at month 9, confirmed at month 12 Limitations: The larger, later trial (SPI2, 642 people) did not confirm the benefit. Pharmaceutical-grade product at a very high dose. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Wolf 2026 Biotinidase Deficiency (GeneReviews) GeneReviews (NCBI Bookshelf) · PMID 20301497 |
Expert review |
Expert clinical review of an inherited disorder in which the body cannot recycle biotin. | Oral free biotin as treatment for the inherited disorder |
People diagnosed before symptoms (for example by newborn screening) and treated with biotin have normal development. Untreated profound deficiency usually shows between age one week and ten years with optic atrophy, low muscle tone, seizures, hair loss and skin rash. Treatment is oral free biotin for life. Some problems such as optic atrophy, hearing loss and developmental delay are usually not fully reversible once they appear. The review gives treatment amounts for specialists, which are not repeated here. Not applicable (Not applicable) Methods, limits and fundingOutcomes: Symptoms, diagnosis and treatment of biotinidase deficiency Limitations: Expert review, not a trial. Applies to the rare inherited disorder only, not to ordinary low intake. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Zhang 2022 Influence of biotin intervention on glycemic control and lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis Front Nutr · PMID 36386951 · DOI |
Systematic review meta analysis |
445 5 randomised controlled trials in adults with type 2 diabetes (445 people in total). |
Biotin supplements 28 to 90 days · vs Control groups (not described in the abstract) |
Fasting glucose: mean difference -1.21 mmol/L (95% CI -2.73 to 0.31). Total cholesterol: -0.22 mmol/L (-0.25 to -0.19). Triglycerides: -0.59 mmol/L (-1.21 to 0.03). Insulin: no significant effect (1.88 pmol/L, -13.44 to 17.21). Evidence for HbA1c, LDL, HDL and VLDL was too limited to conclude. The authors wrote that biotin may lower glucose, total cholesterol and triglycerides; the glucose and triglyceride ranges include zero. FBG -1.21 mmol/L; TC -0.22 mmol/L; TG -0.59 mmol/L (FBG -2.73 to 0.31; TC -0.25 to -0.19; TG -1.21 to 0.03) Methods, limits and fundingOutcomes: Fasting blood glucose, HbA1c, insulin, cholesterol, triglycerides Limitations: Only 5 small, short trials. Two of the three headline results have ranges that include no effect. Not a trial of biotin from food. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| s-fda-biotin-troponin US FDA: Biotin Interference with Troponin Lab Tests - Assays Subject to Biotin Interference · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-medlineplus-biotin MedlinePlus: Pantothenic acid and biotin · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-ods-biotin NIH Office of Dietary Supplements: Biotin fact sheet for health professionals · Source |
Health agency n/a |
Methods, limits and fundingRead: blocked |
What we do not know yet
- No controlled trial of biotin for hair in healthy people was found.
- Food amounts per portion and any official upper limit were not read because the NIH fact sheet was blocked (HTTP 403).
- The FDA safety communication itself could not be opened; only the troponin page was read.
- Contamination and label accuracy of biotin supplements, and kidney or liver safety, were not researched.
- Nail trials were read only through reviews that do not give sizes.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue before the page changes.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Metabolic 1
Total cholesterol and triglycerides
Lower in the pooled estimate for total cholesterol; triglyceride range includes no change in trials
Blood fats measured as part of a heart-risk check.
Very low certaintyResults and what it means
Why it was measured
Often measured in diabetes care.
Statistical vs. clinical meaning
Small and short trials.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 10 | Total cholesterol -0.22 mmol/L (-0.25 to -0.19); triglycerides -0.59 mmol/L (-1.21 to 0.03) | 5 trials, 445 adults with type 2 diabetes | Biotin supplements, 28 to 90 days |
Other 5
Urinary 3-hydroxyisovaleric acid
Raised in marginal biotin deficiency and in anticonvulsant users in trials
A substance passed in urine that rises when a biotin-dependent enzyme works less well.
Low certaintyResults and what it means
Why it was measured
Researchers use it as a more sensitive marker of biotin status than blood biotin.
Statistical vs. clinical meaning
Useful as a research marker; not a test most clinics use in routine care.
Safety implication
Not a safety measure.
| Study | Result | People | Product |
|---|---|---|---|
| 4 | More biotin breakdown products and more 3-hydroxyisovaleric acid in the urine of adults on long-term anticonvulsants | Adults on long-term seizure medicine | Medicine exposure (observational) |
| 5 | About half of pregnant women passed more 3-hydroxyisovaleric acid; the author warns the marker is hard to read in pregnancy | Pregnant women (review) | None (observational) |
Nail firmness, hardness and thickness
Improved with oral biotin in some studies in trials
Measures of how strong a nail is.
Low certaintyResults and what it means
Why it was measured
Brittle nails are the nail problem biotin is most often tested for.
Statistical vs. clinical meaning
Possible, small studies; larger controlled trials still needed.
Safety implication
See Safety for blood-test interference.
| Study | Result | People | Product |
|---|---|---|---|
| 3 | Trials showed improvement in firmness, hardness and thickness of brittle nails with oral biotin (no numbers in the abstract) | Adults with brittle nails | Oral biotin |
Disability score (EDSS) and walking time in MS
No significant improvement in the larger trial in trials
A clinic scale of walking and other disability in multiple sclerosis and a timed 25-foot walk.
Evidence againstResults and what it means
Why it was measured
The main outcomes of the MS trials.
Statistical vs. clinical meaning
The larger trial did not confirm the first.
Safety implication
Lab-test errors were reported in the larger trial.
| Study | Result | People | Product |
|---|---|---|---|
| 8 | 13 (12.6%) improved on biotin vs none on placebo, p = 0.005 | 154 adults with progressive MS | 100 mg biotin (MD1003) three times a day, 12 months |
| 1 | 39/326 (12%) vs 29/316 (9%), OR 1.35 (95% CI 0.81 to 2.26), not significant | 642 adults with progressive MS | 100 mg biotin (MD1003) three times a day, mean 20.1 months |
Fasting blood glucose
Lower in the pooled estimate, but the range includes no change in trials
Sugar level in the blood after not eating.
Very low certaintyResults and what it means
Why it was measured
Used to follow type 2 diabetes.
Statistical vs. clinical meaning
Possible, not established.
Safety implication
Tell your lab and doctor about biotin before blood tests.
| Study | Result | People | Product |
|---|---|---|---|
| 10 | -1.21 mmol/L (95% CI -2.73 to 0.31) | 5 trials, 445 adults with type 2 diabetes | Biotin supplements, 28 to 90 days |
Biotin-dependent enzyme activity (PCC) in blood cells
Low in many pregnant women; raised after biotin in a pilot in trials
A lab measure of how well a biotin-dependent enzyme is working.
Very low certaintyResults and what it means
Why it was measured
Used in pregnancy studies to look for a shortage.
Statistical vs. clinical meaning
Small pilot; interpretation uncertain.
Safety implication
See Safety for pregnancy.
| Study | Result | People | Product |
|---|---|---|---|
| 5 | Low in 18 of 22 pregnant women; mean +95% in 4 of 4 after biotin | Pregnant women | Biotin supplements (pilot) |
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 3
- Biotin can give wrong blood test results. Biotin in supplements can significantly interfere with certain lab tests and cause incorrect results that may go undetected, says the US FDA. In a small study, 10 mg a day for a week gave wrong results in 9 of 23 tests that use biotin. Some tests read falsely high and some falsely low. The FDA reports that falsely low troponin results (a heart attack marker) have been reported. Tell your doctor and the lab if you take biotin, and ask whether to stop before a blood test. Authoritative guidance 11 2 1
- No known toxic symptoms from biotin itself. MedlinePlus states there are no known toxic symptoms from biotin. The NIH fact sheet could not be read, so any official upper limit is not stated here. Authoritative guidance 12 13
- Very high doses in a large MS trial. In the SPI2 trial of 100 mg of biotin three times a day, adverse events were about as common as with placebo (84% vs 85%). One death occurred in the biotin group. The authors described lab-test errors as potentially harmful. Randomised trial 1
Side effects 2
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Wrong results on blood tests that use biotin (thyroid, hormone, vitamin D, heart and other tests) Not a body side effect; a lab effect. Depends on test maker and machine. | 9 of 23 biotin-based tests (39%) in 6 healthy adults on 10 mg a day; none of 14 non-biotin tests | can lead to a wrong diagnosis or missed illness A re-test 7 days after stopping was part of the JAMA study design; the abstract does not report the result. | Small trial and agency 2 11 1 |
| General side effects of biotin supplements Specific side effects are not listed in the abstracts read. | SPI2: 84% adverse events on biotin vs 85% placebo (very high dose) | mostly not different from placebo in that trial Not described in the abstract. | Randomised trial 1 |
Liver
No liver injury from biotin was found in the sources read.
How often. No frequency was found.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Vitamin B7 (biotin) supports liver health.
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Blood and lab tests that use biotin (thyroid, hormone, troponin, vitamin D, PSA, ferritin and others) lab-test | Many tests use biotin and streptavidin to detect a substance. Extra biotin in the blood can block this and make a result falsely high or falsely low. | Can lead to wrong diagnoses. The FDA says some test makers have reduced the problem and others have not. | Small trial and agency Moderate certainty 2 11 1 | Tell your doctor and the lab that you take biotin before any blood test, and ask whether to pause it first. |
| Anticonvulsants (long-term seizure medicines) prescription | Adults on long-term anticonvulsants passed more biotin breakdown products, which the authors took to mean faster biotin breakdown and probably lower biotin status. | A marker study from 1997 without numbers in the abstract; it does not show deficiency disease. | Observational Low certainty 4 | Do not change seizure medicine yourself. Ask your prescriber or pharmacist about supplements. |
| Other medicines and supplements other | Not found. | No other interaction was found in the sources that could be read. The NIH fact sheet, the usual interaction source, was blocked. | Not found Not enough evidence 13 | Ask a pharmacist before combining supplements with medicines. |
Who should check first 2
| Situation | Advice | Evidence |
|---|---|---|
| Before blood tests, especially heart (troponin) or thyroid tests | Tell the doctor and lab about biotin first. In an emergency such as chest pain, tell the care team you take biotin. | Authoritative guidance 11 2 |
| Suspected inherited disorder (infant with seizures, low muscle tone, rash or hair loss) | See a doctor. Biotin is part of specialist treatment but should not be started at home. | Expert review 9 |
Overdose, product quality and regulators
Summary. MedlinePlus states no known toxic symptoms from biotin. The main documented harm of high intake is wrong lab results.
Animal. Not reviewed.
Human doses studied. Trials used 10 mg a day for 7 days (lab-test study) and 300 mg a day for about 20 months (SPI2). These are amounts studied in trials, not advice.
High dose or long term signals. SPI2 reported adverse events similar to placebo and one death in the biotin group; lab-test errors despite mitigation.
Overdose response. Not found.
Genotoxicity. Not researched.
Product quality, label accuracy and contamination of biotin supplements were not researched.
| Body | Action | Date |
|---|---|---|
| US FDA (United States) | Biotin Interference with Troponin Lab Tests: biotin in dietary supplements can significantly interfere with certain lab tests and cause incorrect results that may go undetected; the FDA continues to receive reports of falsely low troponin results and lists troponin tests still subject to interference. source | |
| US National Academies (Food and Nutrition Board), as quoted by MedlinePlus (United States) | Adequate Intake for biotin: 30 mcg a day for adults 19 and older including pregnant women, 35 mcg for breastfeeding women, 5 to 25 mcg for babies and children. This is a reference intake, not advice. MedlinePlus states no known toxic symptoms from biotin and gives no upper limit. source | 2025-01-21 |
When to get medical help
- Chest pain or other heart attack signs: call 911 or your local emergency number, and tell staff you take biotin because it can make some heart test results falsely low.
- An infant with seizures, floppy muscles, or unusual rash or hair loss: seek urgent medical care.
- Results of a blood test that do not match how you feel: ask your doctor whether biotin could be the reason.
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
What is biotin?
Biotin, also called vitamin B7, is a water-soluble B vitamin. Your body needs it to make fatty acids and to use fats, proteins and carbohydrates from food.
What are the signs of low biotin?
Which foods contain biotin?
What is the Adequate Intake for biotin?
MedlinePlus gives 30 mcg a day for adults 19 and older (including pregnant women), 35 mcg for breastfeeding women, and 5 to 25 mcg for babies and children by age. This is a reference level, not advice. MedlinePlus lists no upper limit and says there are no known toxic symptoms.
Does biotin help hair growth?
Not shown in healthy people. A 2017 review found 18 reported cases, all in people with an underlying cause, all improved. It found no sufficient evidence for healthy individuals.
Does biotin strengthen nails?
Can biotin change my blood test results?
Can biotin affect a heart attack test?
The FDA reports that it keeps receiving reports of falsely low troponin results caused by biotin and lists tests that are still affected. If you have chest pain, call emergency services and tell the team you take biotin.
Does biotin treat multiple sclerosis?
Does biotin help with diabetes?
Evidence is very weak. A pooled analysis of 5 small trials found lower total cholesterol, but the ranges for glucose and triglycerides include no effect. Talk with your doctor.
Do seizure medicines affect biotin?
A 1997 study found adults on long-term anticonvulsants passed more biotin breakdown products, which the authors took as probably reduced biotin status. Do not change medicine yourself; ask your prescriber or pharmacist.
Explore by health goal
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Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-26
- Last substantive update
- 2026-10-26
- How we research
- We started from our existing biotin summary, read MedlinePlus and the FDA troponin page, and re-read PubMed abstracts for each study cited. Only abstracts were read for studies. Items we could not verify are flagged in the research gaps.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown. The larger MS trial was funded by the maker of the high-dose biotin product; this is stated where it is used.
Sources 13
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Cree BAC, Cutter G, Wolinsky JS, Freedman MS, et al.. Safety and efficacy of MD1003 (high-dose biotin) in patients with progressive multiple sclerosis (SPI2): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Neurol. 2020. PMID 33222767. DOI 10.1016/S1474-4422(20)30347-1. (abstract)
- Li D, Radulescu A, Shrestha RT, Root M, et al.. Association of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults. JAMA. 2017. PMID 28973622. DOI 10.1001/jama.2017.13705. (abstract)
- Lipner SR, Scher RK. Biotin for the treatment of nail disease: what is the evidence?. J Dermatolog Treat. 2018. PMID 29057689. DOI 10.1080/09546634.2017.1395799. (abstract)
- Mock DM, Dyken ME. Biotin catabolism is accelerated in adults receiving long-term therapy with anticonvulsants. Neurology. 1997. PMID 9371938. DOI 10.1212/wnl.49.5.1444. (abstract)
- Mock DM. Marginal biotin deficiency is common in normal human pregnancy and is highly teratogenic in mice. J Nutr. 2009. PMID 19056637. DOI 10.3945/jn.108.095273. (abstract)
- Mock DM. Biotin: From Nutrition to Therapeutics. J Nutr. 2017. PMID 28701385. DOI 10.3945/jn.116.238956. (abstract)
- Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. 2017. PMID 28879195. DOI 10.1159/000462981. (abstract)
- Tourbah A, Lebrun-Frenay C, Edan G, Clanet M, et al.. MD1003 (high-dose biotin) for the treatment of progressive multiple sclerosis: A randomised, double-blind, placebo-controlled study. Mult Scler. 2016. PMID 27589059. DOI 10.1177/1352458516667568. (abstract)
- Wolf B. Biotinidase Deficiency (GeneReviews). GeneReviews (NCBI Bookshelf). 2026. PMID 20301497. (abstract)
- Zhang Y, Ding Y, Fan Y, Xu Y, et al.. Influence of biotin intervention on glycemic control and lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis. Front Nutr. 2022. PMID 36386951. DOI 10.3389/fnut.2022.1046800. (abstract)
- . US FDA: Biotin Interference with Troponin Lab Tests - Assays Subject to Biotin Interference. . . (full-text)
- . MedlinePlus: Pantothenic acid and biotin. . . (full-text)
- . NIH Office of Dietary Supplements: Biotin fact sheet for health professionals. . . (blocked)
Where to buy
Check the label first. Whatever you buy, look for these:
- The amount of the active ingredient per serving, not just the front-label claim
- A third-party testing mark (USP, NSF or ConsumerLab)
- Other ingredients and allergens
- Ask a pharmacist about interactions with your medicines
Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.
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