Indirect evidence that the action of cyproterone acetate on the skin is due to a metabolite.

Cyproterone acetate, applied as 1% solution in ethanol or isopropyl myristate, did not decrease the sebum excretion rate (SER) when applied to forehead skin of patients with acne, although SER is decreased when the drug is given systemically. The probable explanation is that cyproterone acetate owes its local action to a metabolite formed systemically. The present study shows this is unlikely to be the 17 beta-hydroxy cyproterone acetate.