Biotin May Help Heal Brittle Nails

Biotin's positive effects in treating hoof abnormalities in horses led to speculation on the nutrient's potential benefit in humans with brittle nails. Given the biochemical similarities between horse hooves and human fingernails and toenails, this speculation was not unreasonable, and a number of preliminary clinical studies suggest that biotin does strengthen nails.^{5, 29}

Additionally, both vitamin B6 and biotin help produce keratin - the predominant protein in nails. Biotin is also involved in the production of collagen and elastin, proteins for healthy skin structure beneath the nail.¹⁹

Clinical Evidence of Biotin's Benefits on Brittle Nails

Some experts suggest that taking high doses of biotin daily (2.5 to 5 mg) may help improve nail health. Evidence from a limited number of clinical trials suggests that biotin supplementation may be warranted.^{26, 29}

In an effort to strengthen nails, therapy has typically included increasing water content and topical hardening agents. Research has expanded into substances that may support the health of the underlying nail structure. One small clinical trial showed that oral biotin supplementation (2.5 mg/day) improved brittle nails by increasing healthy thickness by 25% and ameliorating splitting, as compared to an untreated group. All of the test subjects of this 6-15 month trial showed improvement, whereas in another non-controlled study where biotin was used for 1.5-7 months, 67% of patients showed improvement.^{25, 29}

Results of a clinical trial published in 2006 further substantiated biotin's therapeutic effects on brittle nails. The trial involved 54 patients (mostly female) with brittle, split, or soft nails who were divided into two groups - one received 2.5 mg/day of biotin while the other received a placebo. As a double-blind study, neither the researchers nor the patients knew which group they were placed in until the end of the trial. Although the initial trial period of six months showed improvement in nail quality at both three and six months, the results were not statistically significant.²⁵

In another open study involving 45 patients (again, mostly female) with brittle nails, 91% reported firmer nails with less chipping and cracking with 2.5 mg/day of biotin. The remaining participants reported some improvement. However, it did take between three and almost eight months for improvement - which is approximately the amount of time for nail renewal.²⁵