Topterone, is administered parenterally or topically to rats, rabbits or hamsters to determine its endocrine profile. Systemic administration demonstrates that Topterone is both antiandrogenic and progestational. Topical application fails to elicit a systemic antiandrogenic response at 1 g/kg/day and only a minimal progestational response is seen at 32 mg/kg/day. No other endocrine activities are detected. Topterone inhibits stimulation of flank organ development of castrated immature male hamsters by both testosterone and dihydrotestosterone, whereas Progesterone inhibits the stimulation by only testosterone. Topical application of Topterone, has been shown to cause a regression in the development of the flank organ.