Biotin (Vitamin B7)

Also known as: vitamin B7, vitamin H

Hair Restore

In plain English

Biotin is a B-vitamin often marketed for hair, skin, and nails. True biotin deficiency does cause hair loss, and correcting a deficiency helps — but for people who are not deficient (most people), there is little good evidence that extra biotin grows hair. It is generally safe, but it is important to tell your labs and doctors you take it, because biotin can throw off some blood tests (including thyroid and heart-attack tests).

The science

Biotin is a cofactor for carboxylase enzymes in fatty-acid synthesis, gluconeogenesis, and amino-acid metabolism, and biotin-dependent pathways support the keratin infrastructure of hair and nails. Reviews of the literature find clinical improvement with supplementation only in patients with an underlying biotin deficiency or specific pathologies (e.g., brittle nail syndrome, inherited biotinidase/holocarboxylase defects); in otherwise healthy individuals there is no convincing evidence of benefit for hair or nail growth.

References

• Patel DP et al., Skin Appendage Disord 2017 (biotin for hair loss review)
• Lipner SR, J Am Acad Dermatol 2018 (rethinking biotin therapy)