Biotin for Hair Loss: Teasing Out the Evidence.
Level 1 - systematic review of randomized trials
Systematic literature review of clinical trials and cohort studies evaluating oral biotin for hair loss.
What was done
The authors conducted a PubMed search for clinical studies evaluating oral biotin supplementation for hair growth or hair quality, excluding case reports and case series.
What was found
Three studies met the inclusion criteria. The highest-quality study—a double-blind, placebo-controlled trial—found no statistically significant difference between biotin and placebo for hair growth. The remaining two studies evaluated specific cohorts (patients taking isotretinoin and women post-sleeve gastrectomy); both carried multiple potential biases and showed no striking benefit in favor of biotin. The abstract reports no numerical effect sizes.
Why it matters
Despite widespread commercial popularity and public use of biotin as a hair supplement, there is a stark lack of rigorous scientific evidence supporting its efficacy in healthy individuals.
Limits
The review was constrained by an extremely small evidence base (only three eligible studies). The search was limited to a single database (PubMed). Two of the three included studies investigated narrow clinical sub-populations with high susceptibility to bias, and specific quantitative data were not provided in the abstract.
Cited by
- contradicts Biotin applied via shampoo cannot be absorbed through the scalp into the body.