How Does It Work?

Mifepristone works to end a pregnancy by blocking the action of progesterone, a naturally occurring hormone that prepares the lining of the uterus for a fertilized egg and is necessary for pregnancy to continue. When mifepristone blocks progesterone, the lining of the uterus softens and breaks down, ending the pregnancy.
If mifepristone does not cause a complete abortion, misoprostol (Cytotec) is given two days later. Misoprostol is a type of prostaglandin, a hormone-like substance found naturally in the body. It causes the uterus to contract and push out the products of conception.
Mifepristone is also a cortisol receptor blocker. It works in people with type 2 diabetes or glucose intolerance by preventing cortisol from binding to its receptor, thereby reducing the effects of cortisol, such as high blood sugar. Mifepristone does not decrease the production of cortisol by the body.

When and How to Take This Medicine

Some general considerations to keep in mind during treatment with mifepristone include the following:
  • This medication comes in tablet form. It is taken by mouth as a single dose to end a pregnancy. When used in people with Cushing's syndrome, it is usually taken once a day
  • If you are taking this medication for diabetes or glucose intolerance, you should take it with food.
  • If you are taking mifepristone every day, try to take your dose at the same time each day to keep an even level of the drug in your bloodstream.
  • Mifepristone 300 mg tablets should be swallowed whole. Do not cut, crush, or chew the tablets.
  • When used to end a pregnancy, mifepristone should only be taken in a healthcare setting, such as a clinic, medical office, or hospital. You will need to visit your healthcare provider three times so your healthcare provider can make sure your pregnancy has ended.
  • If mifepristone does not end your pregnancy, you will be given another medicine (misoprostol) two days after taking mifepristone.
  • For the medication to work properly, it must be taken as prescribed.
Last reviewed by: Kristi Monson, PharmD
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