TLDR Biotin supplements may improve hair and nail growth in people with certain deficiencies or conditions, but there's not enough evidence to recommend it for healthy individuals.
The review from 2017 examined the effectiveness of biotin for hair and nail growth, finding limited research to support its use in healthy individuals. The literature search, which included case reports and randomized clinical trials, identified 18 cases where biotin supplementation was used for hair and nail issues related to underlying pathologies. These cases showed clinical improvement with biotin treatment. However, the review concluded that while biotin is popularly used for improving hair and nail growth, there is insufficient evidence to recommend its supplementation in healthy individuals, suggesting that the benefits may be limited to those with specific deficiencies or conditions.
71 citations,
January 2016 in “International Journal of Trichology” Biotin deficiency is not a major cause of hair loss in women, so biotin supplements are not likely to be an effective hair loss treatment.
98 citations,
October 2012 in “Dermatologic Clinics” Eating the right nutrients can improve hair health, but taking extra supplements usually doesn't help unless you have a deficiency.
21 citations,
June 2011 in “Journal of child neurology” Valproic acid and carbamazepine do not change biotin or biotinidase levels but may lower zinc levels, still within normal range.
70 citations,
June 2010 in “Clinics in Dermatology” Certain groups may need vitamin supplements to improve hair health and prevent other health problems.
239 citations,
July 2002 in “Clinical and Experimental Dermatology” Low iron and L-lysine levels can cause hair loss in women, and increasing these nutrients can reduce hair shedding.
2 citations,
March 2020 in “PubMed” Biotin deficiency is not a major cause of Telogen Effluvium hair loss.
45 citations,
January 2018 in “International Journal of Dermatology” Nail problems are common in people with alopecia areata, often leading to cosmetic and functional issues, but more research is needed for treatment guidelines.
71 citations,
January 2016 in “International Journal of Trichology” Biotin deficiency is not a major cause of hair loss in women, so biotin supplements are not likely to be an effective hair loss treatment.