Inhibition of Testosterone Conversion to Dihydrotestosterone in Men Treated Percutaneously by Progesterone

ABSTRACT

Unlabeled progesterone was added at different doses to human skin homogenates originating from the pubic area of normal men. The transformation of radioactive testosterone to dihydrotestosterone was inhibited by this in vitro addition of progesterone. In other experiments 100 mg of progesterone dissolved in alcohol was applied upon the skin of 2 normal men. A skin specimen was obtained before and after this topical treatment and incubated with the same procedure as during in vitro experiments. An inhibition of testosterone 5α-reduction to dihydrotestosterone was also observed after this percutaneous administration of progesterone. Thus progesterone, when percutaneously applied upon the skin of human beings, might be useful as an antiandrogen.