Sipinen S, Lähteenmäki P
Ann Clin Res. 1980 Dec;12(6):282-7.
Three different estrogen-progestin regimens were studied in the treatment of menopausal symptoms. Plasma steroid and gonadotropin profiles were determined. As judged by the increase of plasma FSH concentrations, as well as by the decrease of plasma estrone and estradiol concentrations, one treatment-free week during a four week cycle was too long. This FSH increase could not even be eliminated by administering estrogen at half the treatment dose.