A Review of the Use of Biotin for Hair Loss.
Level 4 - case-series / case-control
Systematic review identifying only case reports (no randomized trials)
PubMed 28879195 · doi:10.1159/000462981
What was done
The authors performed a PubMed search for case reports and randomized clinical trials evaluating biotin efficacy in hair and nail growth using search terms related to biotin, supplementation, hair, alopecia, nails, and dermatology.
What was found
The review identified 18 reported cases of biotin use for hair and nail changes. In all 18 cases, patients had an underlying pathology for poor hair or nail growth (inherited or acquired deficiency, brittle nail syndrome, or uncombable hair) and showed clinical improvement after biotin supplementation. No randomized clinical trials or data supporting efficacy in healthy individuals were found.
Why it matters
Despite popular commercial claims for hair and nail enhancement, clinical evidence for biotin is confined to rare deficiency states and specific pathologies, with no evidence supporting use in healthy individuals.
Limits
The evidence base is limited to 18 individual case reports with no randomized controlled trials identified. Case reports lack control comparators and are susceptible to selection and publication biases. The search was restricted to PubMed, and quantitative effect sizes were not reported in the abstract.
Cited by
- contradicts Biotin applied via shampoo cannot be absorbed through the scalp into the body.