Desogestrel, (17а)-13-ethyl-11-methylene-18,19-dinorpregn-4-en-20-yn-17-ol, is a 19-nortestosterone analog with good progestin activity. Likethe other progestins, it is orally active and used in combinationwith an estrogen in oral contraceptives. Desogestrel is aprodrug that must be oxidized to the 3-one in vivo to haveprogestational action. CYPs 2C9 and 2C19 have been implicatedin the initial hydroxylation of desogestrel at C3.
Desogestrel is a prodrug and is rapidly metabolized in the intestinal mucosa and on first pass through the liver to its active metabolite, etonogestrel (3-ketodesogestrel). Following oral administration, the relative bioavailability for desogestrel is approximately 84%. Desogestrel also exhibits high selectivity for the progesterone receptor and low and rogenic activity, and it does not diminish the beneficial effects of estrogen on the lipid profile.
