Ro 6-3129

Ro 6-3129, also known as 16α-ethylthio-6-dehydroretroprogesterone or as 16α-ethylthio-9β,10α-pregna-4,6-diene-3,20-dione, as well as 16α-ethylthiodydrogesterone, is a progestogen of the retroprogesterone group which was developed by Roche but was never marketed. It shows greater potency than dydrogesterone in bioassays.