Part of “CHAPTER 105 – COMPLICATIONS AND SIDE EFFECTS OF STEROIDAL CONTRACEPTION“

Hormonal contraceptives are formulated from synthetic steroid 19-nortestosterone derivatives, which include norethindrone, norethindrone acetate, norethynodrel, ethynodiol diacetate, norgestrel, levonorgestrel (LN), desogestrel, gestodene, norgestimate, and dienogest. Exceptions are the injectable contraceptives (Depo-Provera, Lunelle), which use the progesterone derivative, depot medroxyprogesterone acetate (MPA). One of these progestins is combined with various dosages of an estrogen, either ethinyl estradiol or ethinyl estradiol-3-methyl ether (mestranol) in oral tablets and in some long-acting methods (injectables, vaginal rings, patches). The presence of a C₁₇ ethinyl group on all synthetic estrogens and progestins enhances the oral activities of these agents by slowing their rapid hydroxylation and conjugation in the hepatic portal system.1,2