Biotin for Hair, Skin and Nails: What the Evidence Shows
What reviews found on biotin for hair, skin and nails: helpful in true deficiency and some nail disorders, but little proof in healthy people, plus lab-test cautions.
Content last updated . This page has not been medically reviewed.
What biotin does and when it runs short
Biotin helps the body make fatty acids, and the bacteria in the bowel make some of it. The NHS says it is not clear whether you need extra from food, and that it is found in a wide range of foods at low levels. [2] A review of biotin says frank symptomatic deficiency is rare. [3] Another review lists poor intake, drug and vitamin interactions and inherited problems with how biotin is handled as causes of deficiency. [4] A clinical review lists biotin among the micronutrients whose deficiency can show up in skin, hair and nails. [5]Hair, skin or nail changes have many causes, and these signs alone cannot show a biotin shortage. If you notice hair loss, brittle nails or a rash, see a clinician rather than self-treating with a supplement. The same is true for suspected deficiency of any kind.
What the research found
| Question | What the source found | Strength of evidence |
|---|---|---|
| Hair in healthy people | A review of case reports and trials concluded there is a lack of sufficient evidence for supplementation in healthy individuals. [1] | Insufficient evidence |
| Hair in people with a cause | The same review found 18 cases of biotin use for hair and nail changes, all with an underlying problem, and all improved. It calls such cases uncommon. [1] | Promising but limited (case reports) |
| Brittle nails | A review says trials showed improved firmness, hardness and thickness of brittle nails with oral biotin, and that larger controlled trials are needed. [6] | Promising but limited |
| Biotin deficiency | Inherited and acquired causes of deficiency, and conditions such as brittle nail syndrome or uncombable hair, were the situations where the first review said biotin may be of benefit. [1] | Established role in deficiency |
| Vitamins and minerals for hair loss in general | A review notes the evidence on micronutrients and hair loss is enormous and conflicting. [7] | Mixed |
Case reports have no comparison group, and a trial in people with brittle nails does not show that biotin grows hair in healthy people. Do not transfer findings between these groups.
Proper evidence not found: for randomized trials showing that biotin makes hair grow faster or thicker in adults who have normal biotin status. We searched PubMed for biotin with hair, nails, skin and supplementation, and the review above reached the same conclusion.
Related pages
Biotin (vitamin B7), Collagen, biotin and beauty supplement claims and Skin and hair.Frequently asked questions
Does biotin make hair grow?
In healthy people, a review found limited evidence that it does. [1] In people with a deficiency or specific nail or hair disorders, reports show some benefit.
Can biotin help brittle nails?
A review says trials showed improved firmness, hardness and thickness with oral biotin and called for larger controlled trials. [6] Ask a clinician about causes of brittle nails.
Can I get enough biotin from food?
The NHS says you should be able to get all the biotin you need from a varied and balanced diet. [2]
Is high-dose biotin safe?
The NHS says there is not enough evidence to know the effects of high daily doses. [2] It can also distort some blood tests.
Should I take biotin for hair loss?
Hair loss has many causes. See a clinician first. A review of vitamins and hair loss says micronutrients play an important but not entirely clear role. [7]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read the evidence labels
Labels used on this page: established nutritional role / deficiency treatment, promising but limited, insufficient evidence and Proper evidence not found.
Intake references and safety
- Health Canada's adequate intake is 30 micrograms a day for adults and 35 for breastfeeding women; no upper limit could be set. [8]
- The NHS says taking 0.9 mg or less a day of biotin in supplements is unlikely to cause harm and that there is not enough evidence to know the effects of high daily doses. [2]
- Lab tests: biotin can make some blood tests, including troponin tests used for heart attacks, read falsely. [9] See Biotin and lab-test interference. Tell your clinician if you take it.
- Pregnancy, breastfeeding, children, older adults, kidney or liver conditions, medicines and surgery: we did not find a source we could read that gives biotin-specific advice for these groups, so please ask a clinician or pharmacist. See How medication interactions work.
- Quality: products vary. See Quality testing and certifications.
References
- Patel DP, Swink SM, Castelo-Soccio L. A review of the use of biotin for hair loss. Skin Appendage Disord 2017;3(3):166-169.
- NHS (UK). Vitamins and minerals: B vitamins and folic acid. Page last reviewed 3 August 2020. Read 2026-10-23.
- Mock DM. Biotin: from nutrition to therapeutics. J Nutr 2017;147(8):1487-1492.
- Zempleni J, et al. Biotin and biotinidase deficiency. Expert Rev Endocrinol Metab 2008;3(6):715-724.
- DiBaise M, Tarleton SM. Hair, nails, and skin: differentiating cutaneous manifestations of micronutrient deficiency. Nutr Clin Pract 2019;34(4):490-503.
- Lipner SR, Scher RK. Biotin for the treatment of nail disease: what is the evidence? J Dermatolog Treat 2018;29(4):411-414.
- Almohanna HM, et al. The role of vitamins and minerals in hair loss: a review. Dermatol Ther (Heidelb) 2019;9(1):51-70.
- Health Canada. Dietary reference intakes tables: Reference values for vitamins. Page dated 2025-11-19. Read 2026-10-23 through a web-fetch tool.
- US Food and Drug Administration. Biotin interference with troponin lab tests: assays subject to biotin interference. Content current as of 06/21/2022. Read 2026-10-23.