A randomized, active- and placebo-controlled study of the efficacy and safety of different doses of dutasteride versus placebo and finasteride in the treatment of male subjects with androgenetic alopecia.

BACKGROUND: Dihydrotestosterone is the main androgen causative of androgenetic alopecia, a psychologically and physically harmful condition warranting medical treatment.

OBJECTIVE: We sought to compare the efficacy and safety of dutasteride (type 1 and 2 5-alpha reductase inhibitor) with finasteride (type 2 5-alpha reductase inhibitor) and placebo in men with androgenetic alopecia.

METHODS: Men aged 20 to 50 years with androgenetic alopecia were randomized to receive dutasteride (0.02, 0.1, or 0.5 mg/d), finasteride (1 mg/d), or placebo for 24 weeks. The primary end point was hair count (2.54-cm diameter) at week 24. Other assessments included hair count (1.13-cm diameter) and width, photographic assessments (investigators and panel), change in stage, and health outcomes.

RESULTS: In total, 917 men were randomized. Hair count and width increased dose dependently with dutasteride. Dutasteride 0.5 mg significantly increased hair count and width in a 2.54-cm diameter and improved hair growth (frontal view; panel photographic assessment) at week 24 compared with finasteride (P = .003, P = .004, and P = .002, respectively) and placebo (all P < .001). The number and severity of adverse events were similar among treatment groups.

LIMITATIONS: The study was limited to 24 weeks.

CONCLUSIONS: Dutasteride increased hair growth and restoration in men with androgenetic alopecia and was relatively well tolerated.