19-Aldehydo-4-androstene-3,17-dione: an estrogen precursor that inhibits sebaceous secretion in a rat model.

19-aldehydo-4-androstene-3,17-dione (A; R = CHO), a biogenetic precursor of estrone in the body, has been found to suppress sebum secretion in the ovariectomized testosterone-treated Wistar rat at 1/2000 times the dose of cyproterone acetate required to produce an equivalent effect. The action of this steroid must therefore be analogous to that of an estrogen even though, in striking contrast to estradiol, it is without effect on uterine weight or vaginal cornification. It is postulated that 19-aldehydo-4-androstene-3,17-dione (A; R = CHO) is converted locally into estrone (B) by aromatase present in skin but only in low concentrations in vagina and uterus. The potential of biogenetic precursors (I) of estrogens for therapy of acne or alleviation of the worst effects of skin aging is worth investigation.