High Quality Content by WIKIPEDIA articles! Mifepristone is a synthetic steroid compound used as a pharmaceutical. It is used as an abortifacient in the first two months of pregnancy, and in smaller doses as an emergency contraceptive. During early trials, it was known as 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 and Mifeprex.