estetrol + desogestrel

Estetrol + desogestrel is a combination oral contraceptive that contains two active ingredients: estetrol, a synthetic estrogen, and desogestrel, a progestin. Estetrol acts as an agonist of the estrogen receptor (with moderate affinity for ERα and ERβ), suppressing ovulation by exerting antigonadotropic effects[6][8]. Desogestrel is a prodrug converted to etonogestrel, which binds selectively to the progesterone receptor and inhibits ovulation primarily by suppressing luteinizing hormone secretion[3][5]. The combination works synergistically to prevent pregnancy through inhibition of ovulation, alteration of cervical mucus (making it more difficult for sperm to enter the uterus), and changes in the endometrium that reduce the likelihood of implantation[4][6]. This combination may offer contraceptive efficacy with potentially favorable safety or bleeding profiles compared to other combined oral contraceptives.