What happens during a medication abortion

A medication abortion, often called the abortion pill, uses two medicines taken a day or two apart to end an early pregnancy. Here is what each one does, what you'd feel and what happens to the pregnancy.

The short answer: the first pill, mifepristone, stops the pregnancy from developing. The second, misoprostol, causes cramping and bleeding that pass the pregnancy out of the uterus, usually within a few hours. The FDA has approved this for pregnancies through 10 weeks.

The two medicines

1. Mifepristone

A pregnancy depends on the hormone progesterone to keep the lining of the uterus in place and the pregnancy growing. Mifepristone blocks progesterone. Without it, the lining begins to break down and the embryo or fetus stops developing and detaches from the wall of the uterus.

You may feel little after this first pill. Some have light bleeding or nausea.

2. Misoprostol

Misoprostol is taken 24 to 48 hours later, usually at home, by dissolving tablets in the cheek or under the tongue. It softens the cervix and makes the uterus contract to push out the pregnancy, much like a miscarriage.

What you'd feel, hour by hour

First 1 to 4 hours after misoprostol: cramping and bleeding usually begin. Cramps can be strong. The pregnancy most often passes within about 4 to 6 hours.
The same day: heavy bleeding with clots, which can be larger than a period. Nausea, vomiting, diarrhea, chills or a mild fever are common.
The following days and weeks: bleeding gets lighter but spotting can continue on and off for up to several weeks.

What happens to the pregnancy

Through 10 weeks, the embryo is still small, but it is developing quickly. Cardiac activity can usually be seen on ultrasound from about 6 to 7 weeks, fingers and toes begin forming around 8 to 9 weeks, and by about 9 to 10 weeks all of the essential organs have begun to grow. It passes along with the pregnancy sac and the tissue that lined the uterus, which can look like large blood clots. See fetal development week by week for what has formed at each stage.

Risks and when to get help

Side effects are common, such as nausea, weakness, fever or chills, vomiting, headache or diarrhea, especially on the day of misoprostol. Serious complications are uncommon, but they happen. In U.S. studies reported on the FDA label:

About 97 in 100 people had a complete abortion with the pills alone. About 3 in 100 needed a procedure to finish, including fewer than 1 in 100 whose pregnancy continued.
Serious problems such as bleeding needing a transfusion, hospitalization or serious infection happened to fewer than 1 in 200.
Between about 3 and 5 in 100 went to an emergency room.
The pills work less well the further along the pregnancy is.

The FDA's label carries a boxed warning that serious and sometimes fatal infections and bleeding occur very rarely, and that a serious infection can happen without a fever.

Get medical care right away (call 911 or go to an emergency room) if you:

Soak through two or more thick pads an hour for two hours in a row
Have a fever of 100.4°F (38°C) or higher that lasts more than 4 hours
Have stomach pain, or feel sick with weakness, nausea, vomiting or diarrhea, more than 24 hours after misoprostol. These can be signs of infection even without a fever.

An ultrasound before taking any medicine matters. It confirms how far along you are and rules out an ectopic pregnancy (one growing outside the uterus), which the abortion pill does not treat and which can be life-threatening.

Follow-up

A follow-up visit, blood test or home urine test one to two weeks later checks that the pregnancy has ended. Ordinary pregnancy tests can stay positive for several weeks.

If you've taken the first pill and changed your mind

Call a doctor or a pregnancy center right away, and watch for heavy bleeding. Some pregnancies continue after mifepristone alone. A treatment called abortion pill reversal is offered by some doctors; supporters report pregnancies continuing, while ACOG and a 2023 research review say there isn't enough evidence that it works.

Sources

U.S. Food and Drug Administration. Mifeprex prescribing information (2023) and Questions and answers on mifepristone.
ACOG. Induced abortion (patient FAQ).
MedlinePlus. Fetal development.
ACOG. Medication abortion reversal is not supported by science.

Common questions

How does the abortion pill work?

It's two medicines. Mifepristone blocks progesterone, the hormone a pregnancy needs to keep growing, so the pregnancy stops developing. Misoprostol, taken one to two days later, makes the uterus cramp and empty, much like a miscarriage.

How far along can you be to take the abortion pill?

The FDA has approved it through 10 weeks (70 days) after the first day of your last period. Because dating by period can be off, an ultrasound is the most accurate way to know how far along you are.

Does the abortion pill hurt?

Expect strong cramping and bleeding heavier than a period, usually for several hours after taking misoprostol. Nausea, vomiting, diarrhea, fever and chills are also common that day.

Is the abortion pill the same as the morning-after pill?

No. Morning-after pills (emergency contraception) work before a pregnancy is established, mainly by delaying ovulation. The abortion pill ends a pregnancy that has already implanted.

What if I take the first pill and change my mind?

Contact a doctor or a pregnancy center right away and don't take the second pill until you've talked to someone. Some doctors offer a treatment called abortion pill reversal; ACOG says there isn't enough evidence that it works.

Last updated 2026-11-02. Medical facts on this page are drawn from the sources listed at the end and on our sources page. This is general information, not medical advice.