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Updated: May 16, 2026

Ovariectomy and 17β-estradiol Replacement in Rats and Mice: A Visual Demonstration
Published on: June 7, 2012
A new contraceptive pill containing 17β-estradiol and nomegestrol acetate
Sophie Christin-Maitre1, Emmanuelle Laroche, Léopoldine Bricaire
1Reproductive Endocrine Unit, Hôpital Saint-Antoine, Université Pierre et Marie Curie, 75012 Paris, France. sophie.christin-maitre@sat.aphp.fr
Abstract:
Most combined oral contraceptive pills contain ethinyl estradiol (EE) with progestins. In order to minimize the pill's cardiovascular risks, the concept of using 17β-estradiol (E2), the endogenous estradiol, arose in the 1970s. Many attempts to develop a pill containing 17β-E2 have failed as cycle control was low. The first pill containing 17β-E2 was launched in 2011. This monophasic pill contains 24 pills with 1.5 mg 17β-E2 and 2.5 mg nomegestrol acetate, and four placebo pills. Studies conducted in Europe and the USA demonstrate that its Pearl index is 0.38 and 1.13, respectively. It has less influence on hemostasis, fibrinolysis markers, lipids and carbohydrate metabolism than the combined oral contraceptive levonorgestrel/EE (150 g/30 g and 100 µg/20 µg). Withdrawal bleedings are shorter and lighter as compared with women using drospirenone/EE (3 mg/ 30 µg). The number of women without withdrawal bleeding is approximately 30% after 12 months. Even though its contraindications are identical to other combined oral contraceptives, this nomegestrol acetate/E2 pill should be considered to be of interest for many women.
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