Dydrogesterone

Dydrogesterone (INN, USAN, BAN), is also chemically known as 9β,10α-pregna-4,6-diene-3,20-dione. Dydrogesterone (6-dehydro-retroprogesterone) is a hormonally active, non-androgenic steroid that was developed in the 1950s.

Dydrogesterone has selective progestational activity and does not inhibit ovulation. The greater rigidity of dydrogesterone also positively affects its selectivity, while natural progesterone is less selective, existing in different conformations that more easily bind to different receptors. As a consequence of its better bioavailability and the progestational activity of its main metabolites (20-, 21- and 16-hydroxy derivatives), the equivalent dose of dydrogesterone is 10–20 times lower than that of oral micronized progesterone.