20α-Dihydrodydrogesterone (20α-DHD), also known as 20α-hydroxydydrogesterone, as well as 20(S)-hydroxy-9β,10α-pregna-4,6-dien-3-one, is a progestin and the major active metabolite of dydrogesterone.[2][1][3] It appears that dydrogesterone is a prodrug of 20α-DHD, as it is largely transformed into this metabolite when given orally in humans.[3] 20α-DHD has progestogenic activity similarly to dydrogesterone, but is less potent in comparison.[3]
^Olbrich, Matthias; Weigl, Kevin; Kahler, Elke; Mihara, Katsuhiro (2016). "Dydrogesterone metabolism in human liver by aldo-keto reductases and cytochrome P450 enzymes". Xenobiotica. 46 (10): 868–874. doi:10.3109/00498254.2015.1134852. ISSN0049-8254.
^ abcRižner TL, Brožič P, Doucette C, Turek-Etienne T, Müller-Vieira U, Sonneveld E, van der Burg B, Böcker C, Husen B (May 2011). "Selectivity and potency of the retroprogesterone dydrogesterone in vitro". Steroids. 76 (6): 607–15. doi:10.1016/j.steroids.2011.02.043. PMID21376746.