Estrogenic absorption through the skin: an experimental study.

Our results show in an unquestionable way that both the steroid (ethinylestradiol) and non-steroid (Ralone) estrogens studied by us were absorbed percutaneously by the rat. They also demonstrate that both estrogens affected target organs in a quite similar way being proportionally dependent upon the 1-to-1,000 ratio existing between them, as established on the basis of a known activity parameter. When one of the two estrogens is given for therapeutical purposes its systemic effects are of a dose-related type.