Is biotin beneficial for hair growth?

Research on biotin for hair growth is highly limited. Although biotin has been included in multicomponent supplements for hair loss,^[1] no clinical trials have looked at the effect of biotin alone on hair growth or hair loss. Biotin deficiency often results in hair loss, but biotin deficiency is extremely rare, meaning it can’t be assumed that biotin will improve hair health in the vast majority of people.^[2] Still, one study found that low biotin levels (<100 ng/L) were common among women with hair loss due to telogen effluvium.^[3] Unfortunately, until clinical trials are performed, it is premature to say whether supplementation with biotin can promote hair growth.