Mifepristone (Mifeprex) is an oral tablet that may be used with misoprostol tablets to end a pregnancy that is 10 weeks or less (70 days or less since the start of your last period). Mifepristone is used in combination with misoprostol (Cytotec ®) to end an early pregnancy. Mifepristone is in a class of medications called antiprogestational steroids. It works by blocking the activity of progesterone, a substance your body makes to help continue pregnancy. Mifepristone is used in a regimen together with misoprostol to end a pregnancy that is less than 70 days in duration. It works by stopping the supply of hormones that maintains the interior of the uterus. Mifepristone, also called “the abortion pill,” is a U.S. FDA-approved oral medication used—along with misoprostol—in a two-drug regimen to end a pregnancy up to 70 days into gestation. Learn about the side effects of mifepristone, from common to rare, for consumers and healthcare professionals. The “abortion pill” is the popular name for a safe and effective way to end an early pregnancy using a combination of two medicines: mifepristone and misoprostol. Mifepristone stops the pregnancy from growing. After taking mifepristone, you take a second medicine (misoprostol) up to 48 hours later. 1.2Cushing's syndrome. 1.3Medical management of early pregnancy loss. 1.4Other uses. 2Side effects. Toggle Side effects subsection. 2.1Pregnancy. 3Pharmacology. View mifepristone information, including dose, uses, side-effects, renal impairment, contra-indications, monitoring requirements and drug action. What is mifepristone and how does it work? Mifepristone is a drug that blocks a hormone called progesterone that is needed for a pregnancy to continue. Overview: Mifepristone is an oral tablet used to end a pregnancy during the first 10 weeks of pregnancy. Mifepristone works by blocking a hormone needed to maintain a pregnancy. Common side.