A medical abortion, also known as medication abortion or non-surgical abortion, occurs when drugs (medication) are used to bring about an abortion. Medical abortions are an alternative to surgical (also called procedural or instrumentation) abortions such as vacuum aspiration or dilation and curettage. Medical abortions are more common than surgical abortions in most places around the world.

Medical abortions are most commonly performed by administering a two-drug combination: mifepristone followed by misoprostol. This two-drug combination is more effective than other drug combinations. When mifepristone is not available, misoprostol alone may be used in some situations.

Medical abortion is both safe and effective throughout a range of gestational ages, including the second and third trimester. It gets progressively riskier and less effective as the pregnancy advances, especially in third trimester. In the United States, the mortality rate for medical abortion is 14 times lower than the mortality rate for childbirth, and the rate of serious complications requiring hospitalization or blood transfusion is less than 0.4%. Medical abortion can be administered safely by the patient at home, without assistance, in the first trimester. However, access to at home use varies by country and jurisdiction depending on legal, regulatory, and medical guidelines. In the second trimester and beyond, it is recommended to take the second drug in a clinic, provider's office, or other supervised medical facility.

For medical abortion up to 12 weeks' gestation, the recommended drug dosages are 200 milligrams of mifepristone by mouth, followed one to two days later by 800 micrograms of misoprostol inside the cheek, vaginally, or under the tongue. The success rate of this drug combination is 96.6% through 10 weeks' pregnancy.

Medical abortion performed very early, before the pregnancy can be detected by ultrasound, is just as safe and effective as medical abortion after the pregnancy is detectable by ultrasound. Misoprostol should be administered 24 to 48 hours after the mifepristone; taking the misoprostol before 24 hours have elapsed reduces the probability of success. However, one study showed that the two drugs may be taken simultaneously with nearly the same efficacy.

For pregnancies after 9 weeks, two doses of misoprostol (the second drug) makes the treatment more effective. From 10 to 11 weeks of pregnancy, the National Abortion Federation suggests second dose of misoprostol (800 micrograms) four hours after the first dose. If the pregnancy involves twins, a higher dosage of mifepristone may be recommended.

After the patient takes mifepristone, they must also administer the misoprostol. While there is a chance for the pregnancy to successfully abort, failure to take the misoprostol may result in any of these outcomes: the fetus may be terminated, but not fully expelled from the uterus (possibly accompanied by hemorrhaging) and may require surgical intervention to remove the fetus; or the pregnancy may continue with a healthy fetus. For those reasons, misoprostol should always be taken after the mifepristone.

In the first trimester, self-administered medical abortion is available for patients who prefer to take the abortion drugs at home without direct medical supervision (in contrast to provider-administered medical abortion where the patient takes the second abortion drug in the presence of a trained healthcare provider). Self-administered medical abortion during the first trimester is as safe and effective as provider-administered abortion.