Efficacy and safety of oral spironolactone for female pattern hair loss in premenopausal women: a randomized, double-blind, placebo-controlled, parallel-group pilot study.

BACKGROUND: Oral spironolactone is widely used as an alternative treatment for female pattern hair loss, particularly in women of reproductive age. However, published data on its effects are still limited. OBJECTIVE: This study aimed to evaluate the efficacy and safety of spironolactone 100 mg daily for female pattern hair loss in premenopausal women compared with placebo. METHODS: Forty-eight women aged 21 to 45 years were randomly assigned to receive spironolactone 100 mg or matched placebo once daily for 24 weeks. Twice-daily minoxidil 3% solution was used for all to avoid untreated participants. Efficacy was assessed by changes in hair density and diameter using videodermoscopy and global photographic assessment. RESULTS: After treatment, hair density and diameter increased significantly in both treatment groups (all P < 0.001). The spironolactone group showed a greater increase in changes from baseline of terminal hair counts (9.48 ± 11.25 vs 5.32 ± 6.81 hairs/cm2) and hair diameters (4.23 ± 4.58 vs 2.96 ± 2.84 μm), compared with the placebo group. However, only the P-value of terminal hair counts approached the cutoff of statistical significance (P = .063). The spironolactone group also showed greater moderate-to-marked improvement than the placebo group (38% vs 9%; P = .034). Adverse events, primarily menstrual irregularities (37.5%), were significantly higher in the spironolactone group. LIMITATIONS: The sample size was small. CONCLUSION: Oral spironolactone 100 mg daily for 24 weeks showed an additive effect on topical minoxidil therapy in premenopausal women with mild-to-moderate female pattern hair loss. Although it was generally well-tolerated, irregular menstruation was common.