A randomized, placebo-controlled trial of 5% and 2% topical minoxidil solutions in the treatment of female pattern hair loss

Background: Topical minoxidil solution 2% stimulates new hair growth and helps stop the loss of hair in men with androgenetic alopecia and women with female pattern hair loss. Results can be variable, and historic experience suggests that higher concentrations of topical minoxidil may enhance efficacy. Objective: The purpose of this 48-week, double-blind, placebo-controlled, randomized, multicenter trial was to compare the efficacy and safety of 5% topical minoxidil with 2% topical minoxidil and placebo in the treatment of female pattern hair loss. Methods: A total of 381 women (18-49 years old) with female pattern hair loss applied 5% topical minoxidil solution (n = 153), 2% topical minoxidil solution (n = 154), or placebo (vehicle for 5% solution; n = 74) twice daily. Primary efficacy variables were change in nonvellus hair count at week 48, and patient and investigator assessments of change in hair growth/scalp coverage at week 48. Results: After 48 weeks of therapy, 5% topical minoxidil was superior to placebo for each of the 3 primary efficacy measures. The 2% topical minoxidil group demonstrated superiority over placebo for hair count and investigator assessment of hair growth/scalp coverage at week 48; differences in patient assessment of hair growth at week 48 were not significantly different from placebo. The 5% topical minoxidil group demonstrated statistical superiority over the 2% topical minoxidil group in the patient assessment of treatment benefit at week 48. Both 5% and 2% topical minoxidil helped improve psychosocial perceptions of hair loss in women with female pattern hair loss. An increased occurrence of pruritus, local irritation, and hypertrichosis was observed with 5% topical minoxidil versus 2% topical minoxidil and placebo. Conclusion: In this 48-week study of 381 women with female pattern hair loss, 5% topical minoxidil was superior to placebo on each of the 3 primary efficacy end points: promoting hair growth as measured by change in nonvellus hair count and patient/investigator assessments of hair growth and scalp coverage. Application of 2% topical minoxidil was superior to placebo for assessments of nonvellus hair counts and investigator assessment of hair growth/scalp coverage at week 48; differences in patient assessment of hair growth at week 48 were not significantly different from placebo. At week 48, the 5% topical minoxidil group demonstrated statistical superiority over the 2% topical minoxidil group in the patient assessment of treatment benefit. Both concentrations of topical minoxidil were well tolerated by the women in this trial without evidence of systemic adverse effects. With the introduction of numerous herbal remedies for hair loss, of which most have not been tested in randomized, double-blind, placebo-controlled trials, it is important to describe well-controlled trials that demonstrate the efficacy and safety of topical drugs.