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Mifepristone is a pill that can be taken as an alternative to a surgical abortion.


This medication most often is used for ending early pregnancies. In 2003, studies were surfacing reporting other possible uses for mifepristone, at least at low doses. These studies included its possible use in treating psychotic depression. Low-dose mifepristone also showed success as a treatment for uterine fibroids, or benign growths in the muscular tissue of a woman's uterus. However, many uses of the drug other than for abortions were still experimental, even if promising.

Mifespristone's primary use for medical abortions is preferred by many over surgical approaches to abortions. It has emerged as a form of emergency contraception when taken at low does within a short time period following possible conception.


Women who are more than seven weeks pregnant (or 49 days since their last menstrual period) should not take mifepristone. Other reasons to avoid mifepristone include: use of an intrauterine device (IUD), ectopic pregnancy, use of blood thinners, bleeding disorders, use of steroid medications, allergies to mifepristone or similar drugs and lack of access to medical help within two weeks after the treatment. When the drug is used at low doses as emergency contraception, it poses few side effects.


Mifepristone, sold commercially under the name Mifeprex, also is known as RU-486, the abortion pill, the early option pill for medical abortion. While it has been used for many years in Europe, mifepristone has only been available for use in the United States since the U.S. Food and Drug Administration (FDA) approved it in 2000 for use in abortion. More than 37,000 abortions were performed using the pill in the first six months of 2001.

This drug causes pregnancy to end by blocking the female hormone progesterone. The lack of progesterone makes the uterus shed its lining, which causes bleeding similar to a menstrual period. Three days after taking mifepristone, women are given a second drug, misprostol, to cause uterine contractions that expel the contents of the uterus. Most women are able remain in their own home while they pass the fetus.


Before taking mifepristone, health care providers likely will give the woman a urine or blood test to be sure that she is, in fact, pregnant. They also may give her some counseling and support. Once she has made the decision to use mifepristone, they will ask her to sign a written statement that she has decided to end her pregnancy.


Using mifepristone and misoprostol causes heavy bleeding and cramping. Doctors can offer pain medicine, such as Motrin, to ease the cramps. For two weeks after treatment with mifepristone, health care providers likely will ask patients to abstain from sexual intercourse, heavy lifting and strenuous exercise. They also may advise against breast-feeding, since scientists are not sure if the drug is present in breast milk.

Physicians require patients to come in for a follow-up visit 14 days after their first dose of mifepristone to verify that they are no longer pregnant and that they are properly healing.


Other common side effects include: fatigue, headaches, dizziness, nausea, vomiting, diarrhea and low-back pain.

Since pregnancy hormones are in flux after a medical abortion, many women have emotional side-effects, such as mood swings, depression or a mild case of the blues. These feelings usually subside when hormones stabilize a few weeks later. For those who feel stuck in their grief or anger about the situation, counseling or support groups may offer relief.

Normal results

Most women feel better after about two weeks. Bleeding and spotting usually occurs for 9-16 days, but may last for a month.

Abnormal results

In some cases, mifepristone does not completely end the pregnancy. If the fetus is still left inside the uterus, a doctor may recommend a surgical abortion, or a procedure called dilation and curettage (D and C). About five to eight of every 100 women who take mifepristone go on to have a surgical abortion, according to the FDA. During a D and C, which usually is done at a hospital or clinic under a local anesthetic, a physician dilates the cervix, then uses an instrument to scrape any residual tissue away from the walls of the uterus. This allows the heavy bleeding to eventually stop so a woman can return to her normal cycle sooner.


Dilation and curettage (D and C) During this surgical procedure, a physician dilates the cervix, then uses an instrument to scrape tissue away from the walls of the uterus.

Misprostol A drug used in combination with mifepristone to cause uterine contractions that expel the contents of the uterus.



"Abortion Pills Account For 5% of U.S. Abortions." Medical Letter on the CDC and FDA February 9, 2003: 7.

"The Abortion Pill's Grim Progress." Mother Jones 24 (January 1, 1999).

Grimes, David A, Mitchell D. Creinin. "Induced Abortion: an Overview for Internists." Annals of Internal Medicine April 20, 2004: 620-627.

"Low-dose Mifepristone Blocks Pregnancy by Altering Ovarian Function." Drug Week March 5, 2004: 107.

"Treatments for Depression with Psychosis." Harvard Mental Health Letter August 2003.

Walling, Anne D. "Low-dose Mifepristone Shrinks Uterine Fibroids." American Family Physician September 1, 2003: 956.

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mifepristone (mi-fep-ris-tohn) n. a drug used to produce a medical abortion; it acts by blocking the action of progesterone, which is essential for maintaining pregnancy. It is taken by mouth, followed after 36–48 hours by gemeprost intravaginally. Trade name: Mifegyne.

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