How is a medication abortion performed?
In a medication abortion, sometimes called a medical or chemical abortion, a woman is administered an abortion-inducing compound called mifepristone (also called RU-486 or Mifeprex). Mifepristone blocks the action of progesterone, the natural hormone vital to maintaining the lining of the uterus. As the nutrient lining disintegrates, the embryo starves. Subsequently, the woman takes a dose of artificial prostaglandins which initiate uterine contractions and cause the embryo to be expelled from the uterus. Abortions by mifepristone are usually done prior to 49 days after the woman’s last menstrual period, but are sometimes done as late as 70 days.
Willke, John, MD and Barbara Willke. Abortion: Questions & Answers. Cincinnati: Hayes, 2003.