What Is RU 486?
RU 486 (or Mifepristone) is a steroid hormone similar in structure to the natural hormone progesterone. Invented in 1980 by Dr. Etienne-Emile Baulieu for the French pharmaceutical company Roussel-Uclaf, RU 486 is the first of a new generation of birth control drugs called "antiprogestins", considered to be a breakthrough in birth control technology. (RU 486's name comes from Roussel-Uclaf's initials plus a serial number.)