Mifepristone

Mifepristone is a synthetic steroid compound used as a pharmaceutical. It is a progesterone receptor antagonist used as an abortifacient in the first months of pregnancy, and in smaller doses as an emergency contraceptive. Mifepristone is also a powerful glucocorticoid receptor antagonist, and has occasionally been used in refractory Cushing's Syndrome (due to ectopic/neoplastic ACTH/Cortisol secretion). During early trials, it was known as RU-38486 or simply RU-486, its designation at the Roussel Uclaf company, which designed the drug. The drug was initially made available in France, and other countries then followed—often amid controversy. It is marketed under tradenames Mifegyne, Zacafemyl and Mifeprex.