Comprehensive Overview of the Abortion Pill

woman at medical consult

The abortion pill, mifepristone, is prescribed for medical termination of early pregnancies. It is easy and safe to use under strict expert medical guidance and is an effective alternative to an invasive surgical abortion.

The Medical Abortion Pill

(Mifeprex™), the medical abortion pill (first known as RU486), comes as a 200 milligram (mg) oral tablet. The U. S. Food and Drug Administration (FDA) approved mifepristone in 2000 for aborting pregnancies up to 49 days (seven weeks) from the last menstrual period. However, based on research evidence on effectiveness and safety, doctors in some states will prescribe it for women up to 63 days (nine weeks) pregnant.

Other Uses

Doctors also give mifepristone to expel nonviable early intrauterine pregnancies, for labor induction, and to treat other problems. Don't confuse the abortion pill with the morning after pill, or emergency birth control, which is a contraceptive that prevents pregnancy.


A doctor or a doctor-supervised family planning provider gives you mifepristone in an office, hospital, or abortion clinic, which decreases the risk of diversion, misuse, and adverse effects. As of February, 2016, in 37 states in the U. S., the abortion pill can only be prescribed by a doctor, and there are other state-by-state restrictions.

You cannot get mifepristone for an abortion from a pharmacy because of U. S. Food and Drug Administration (FDA) regulations and the drug company's medical prescriber restrictions. It is unsafe to buy the pill on the Internet or elsewhere and use it without expert supervision.


According to the Guttmacher Institute, a mifepristone medical abortion costs $490, about the same as a surgical abortion. Your cost will depend on your health insurance coverage and the state where you live.

How Mifepristone Works

According to the producer of the drug, mifepristone blocks progesterone from working in the uterus. It binds tightly to progesterone receptors and effectively prevents the hormone from binding to its uterine sites. This causes the uterine lining and the site of implantation to break down and the embryo or fetus to stop growing. Mifepristone also contracts uterine muscle and softens (ripens) the cervix.

A Second Drug

After you take mifepristone you are given a second drug, misoprostol, which comes as a 200 microgram (ug) tablet and is cheaper than mifepristone. It causes the mifepristone-primed uterus to contract more and expel the pregnancy and endometrium. Misoprostol is a relative (analogue) of prostaglandin and has multiple uses in obstetrics and gynecology.

How The Drugs are Taken

Mifepristone oral tablet is taken only by mouth. However, oral misoprostol can be swallowed, placed under the tongue (sublingual), between the cheeks and gums (buccal), or inside the vagina.

Medical Abortion Regimens

According to an American Congress of Obstetricians and Gynecologists (ACOG) Practice Bulletin, the following are two examples of mifepristone-misoprostol medical abortion regimens:

  • The FDA-approved regimen: Mifepristone 600 mg (three tablets) is taken by mouth in the family planning office or abortion clinic. You return 48 hours later for misoprostol 400 ug (two tablets) by mouth.
  • An evidenced-based alternate regimen: Mifepristone 200 mg (one tablet) taken by mouth in the office is followed by misoprostol 800 ug (four tablets) by vaginal, buccal, or sublingual routes, taken at home 24 to 48 hours later. Alternatively, vaginal misoprostol may be used at the time of the mifepristone or six hours or less later.

The pregnancy aborts in less than 24 hours after the misoprostol dose - most often in three to four hours. After completing the regimen, you return to the office or clinic for follow-up two weeks later to ensure the abortion is complete.

Mifepristone Versus Surgical Abortion

Compared to surgical termination of pregnancy, mifepristone medical abortion is less invasive, can be done earlier, is cheaper, and does not require anesthesia.


Based on a 2011 Cochrane Library database analysis, mifepristone-misoprostol regimens are all effective for terminating a pregnancy. However, according to the ACOG Practice Bulletin, the evidence-based protocols have a higher success rate:

  • The FDA protocol has a 92 percent abortion rate.
  • The evidenced-based protocols have a 95 to 99 percent success rate.

The abortion rate depends on:

  • The dose of the drugs
  • By which route the misoprostol is used
  • The weeks of gestation: The abortion rate decreases with advancing weeks from the last period

In addition, the evidence-based regimens use a lower dose of mifepristone, costs less, and have fewer side effects from vaginal compared to oral misoprostol.

Side Effects of the Abortion Pills

According to data submitted to the FDA by the manufacturer of mifepristone, pain and vaginal bleeding are the most common symptoms of combined mifepristone-misoprostol abortion. These are necessary effects to abort the pregnancy.

Other side effects last only a few days and depend on the dose of the pills. They include:

  • Nausea, vomiting, and diarrhea: These symptoms are less with vaginal misoprostol than by the oral routes.
  • Headaches, dizziness, and fatigue
  • Mild fever, chills, or hot flashes

You can manage the pain with ibuprofen, or you may get a prescription for a narcotic to take if needed. Bleeding, which may be heavier than a normal period, lasts an average of nine days, but some women have spotting for up to one month.

Adverse Effects

Based on the drug manufacturer's data, studies on mifepristone-misoprostol abortions showed the most common adverse effects include:

  • Excessive vaginal bleeding: Soaking two maxi pads in one hour for two hours is considered excessive and requires early medical attention.
  • Failure to pass the fetus, which may require a surgical evacuation. This risk increases with the gestational age of the pregnancy.
  • Incomplete abortion resulting in retained fetal tissue or clots
  • Unrecognized ectopic pregnancies
  • Allergy to the pills

Mifepristone may interact adversely with antibiotics, antifungals, anticonvulsants, and over-the-counter medicines, such as St John's Wort.

Infection and Death

An FDA bulletin updated in 2011 notes that, after approval of mifepristone in 2000, there have been reports of blood infection (sepsis) and four deaths following medical abortions. It is not clear whether this outcome was caused by the drugs, according to the FDA.

According to a U. S. National Library of Medicine summary, after starting a medical abortion you should contact your healthcare provider if your temperature is above 100.4 for more than 4 hours, especially if you feel generally unwell and have shaking chills and increasing abdominal pain.


The mifepristone medication guide lists several contraindications to taking the drug, including:

  • More than seven weeks of pregnancy (or nine weeks based on the ACOG Practice Bulletin cited previously)
  • Confirmed or suspicion of an ectopic pregnancy
  • IUD in place (can be removed before taking the pill)
  • Have problem clotting blood or are on blood thinners
  • Take corticosteroids or have chronic adrenal failure
  • Allergy to mifepristone or misoprotol
  • Unreliable for follow-up visits and live too far from a medical facility in case of emergency

According to the ACOG Practice Bulletin, healthcare providers may also exclude women for:

  • Other medical conditions, such as anemia, kidney, liver, lung or heart disease, or high blood pressure.
  • Psychosocial reasons, such as inability to understand the medication or the procedure and risks, sign a consent, or follow strict safety instructions

If you are currently breastfeeding, note also that mifepristone is secreted in breast milk.

Medical Guidance

Review the risks and benefits of the abortion pill and the medical abortion process with your doctor or a family planning service provider. Mifepristone is effective and safe if you have no contraindications and take it under expert medical guidance.

Comprehensive Overview of the Abortion Pill