Topical Minoxidil: Systematic Review and Meta-Analysis of Its Efficacy in Androgenetic Alopecia

Topical minoxidil has become a mainstay in the treatment of androgenetic alopecia (AGA). Despite being a longstanding treatment for AGA, relatively few reviews of its efficacy have been published. The current study sought to synthesize the available efficacy data by performing a systematic review of the literature and conducting random-effects pairwise meta-analyses for the outcomes percent increase in hair count from baseline, investigator assessment, and patient self-assessment. Results showed that minoxidil is more effective than placebo in promoting total and nonvellus hair growth (mean difference [MD], 16.68; 95% confidence interval [CI], 9.34-24.03 and MD, 20.90; 95% CI, 9.07-32.74). A significantly higher proportion of participants in the minoxidil group had greater hair growth than participants in the placebo group as judged by both investigators and self-reports (relative risk [RR], 2.28; 95% CI, 1.58-3.31 and RR, 1.56; 95% CI, 1.34-1.80). Despite significant clinical efficacy, cosmetically acceptable results are present in only a subset of patients. Compliance is thought to be a major limiting factor and is being addressed by novel formulations and combinations.