Influence of 2 Mg Estradiol-17β on Circulating FSH, LH, Total and Unconjugated Estradiol Levels in Post—Menopausal Women

The 24-hour Variation in Total and Unconjugated Serum Estradiol-17β as Well as the daily variation in one-hour serum concentration values of FSH and LH have been examined in 9 post-menopausal women given 2 mg tablets of estradiol-17β daily for 14 days. The tablets were manufactured according to a new dispersion method aiming at producing essentially smaller crystals, thereby enhancing the bioavailability of the estradiol-17β. In comparison with other preparations, this one provides a more rapid absorption, reaching peak effect after only 1 or 2 hours and presenting a higher peak than has been found with any of the others. The elimination from serum combines a rapid initial phase followed by a very slow one. Thus serum levels of estradiol-17β 24 hours after administration are significantly higher than the levels measured before administration of the first tablet. A rather small but significant reduction in serum LH and FSH was observed on the third and subsequent treatment days.