Comparative evaluation of the androgenicity of four low-dose, fixed-combination oral contraceptives

Abstract

Changes in endogenous androgen metabolism were compared in healthy women taking one of four low-dose modern oral contraceptives (OCs). One hundred women were randomized to (1) 35 micrograms ethinyl estradiol (EE) + 250 micrograms norgestimate (Cilest); (2) 20 micrograms EE + 150 micrograms desogestrel (Mercilon); (3) 30 micrograms EE + 150 micrograms desogestrel (Marvelon); or (4) 30 micrograms EE + 75 micrograms gestodene (Femodene). During the luteal phase of the pretreatment cycle, body weight and blood pressure were recorded, and plasma levels of the following variables were recorded: sex-hormone-binding globulin (SHBG), cortisol-binding globulin (CBG), testosterone, free testosterone, dihydrotestosterone, androstenedione, dihydroepiandrosterone sulfate (DHEAS), and hydroxyprogesterone. The free androgen index was also calculated. These variables were remeasured during the third week of OC intake and during the fourth and sixth cycles. There were no statistically significant differences in androgenic variables among the four OCs. The DHEAS concentration decreased less with the 20 micrograms EE + desogestrel formulation compared with either 30 micrograms EE + desogesterel or norgestimate-containing formulations (20% vs. 45%). Concentrations of SHBG and CBG increased significantly in all four groups (average 263 +/- 119% and 94 +/- 26%, respectively); CBG increased less in women taking 20 micrograms EE + desogestrel (about 75%) than in the other formulations (about 100%). The four modern, low-dose OCs tested had similar impacts on endogenous androgen metabolism, yielding significant decreases in testosterone, dihydrotestosterone, androstenedione, and DHEAS. All of these formulations may be beneficial in women with androgen-related syndromes such as acne and hirsutism. Large studies are under way to establish which of the third-generation OCs is the least androgenic. In vitro studies suggest that norgestimate has the least androgenic profile.