Fifty-seven men were randomly assigned for treatment of androgenetic alopecia with viprostol, vehicle, or placebo twice daily for 24 weeks. Nonvellus hair growth was assessed subjectively by both patient and investigator and objectively through hair counts from macrophotographs of the target area. Nonvellus target area hair counts declined in all three treatment groups at the end of the 6-month study. Viprostol is not an effective hair growth promoter in androgenetic alopecia.