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How Do Abortion Pills Work? - Medical Abortion: Medication Risks & Recovery

Around the world, people are more and more often choosing medication, rather than a clinical procedure, to end unwanted pregnancies.

Pill-based abortions now account for more than half of all abortions in the US, and that figure is even higher in other countries.

So what are these medications, and how do they work?

Globally, the most common medication used to end pregnancies is called misoprostol.

Misoprostol was originally developed to treat ulcers, since it interacts with the muscular lining of the stomach and affects the secretion of important stomach fluids. But misoprostol also interacts with the muscular lining of the uterus and there, it causes contractions, which can push out everything inside. When taken during the first ten weeks, misoprostol alone will end a pregnancy about 90% of the time.

Misoprostol can also be used in combination with another medication called mifepristone, which was originally called “RU-486.” Mifepristone works by interfering with the pregnancy hormone that normally keeps the lining of the uterus thick enough to support a growing embryo and keeps the cervix - the opening to the uterus - closed off. By binding to the hormone’s receptors, mifepristone blocks the hormone from doing those jobs.

As a result, the uterine lining starts breaking down - causing the embryo to detach - and opening to the uterus starts softening, making it easier for contractions to push out everything inside.

Mifepristone, the hormone-blocker, isn't all that effective at ending pregnancies on its own. But because it has such a different mechanism from misoprostol, the contraction-causer, the two medications are really effective together; if taken during the first ten weeks, these two types of pills in combination will end a pregnancy more than 95% of the time.

Pill-based abortions can be pretty painful and cause a lot of bleeding; after all, what these medications are doing is causing a miscarriage. Medical professionals can’t actually tell from symptoms alone whether someone is having a natural miscarriage or a pill-based abortion, since the physiological process is exactly the same.

In fact, doctors routinely prescribe mifepristone and misoprostol to people in the midst of miscarriages, since they can help the tissue detach and pass out of the body more quickly and safely. When taken according to instructions, these medications are a remarkably safe way to end a pregnancy: most of the bleeding and discomfort resolve on their own within a day or two. A very small percentage of people do experience complications - like they lose too much blood, or their body doesn’t pass all the pregnancy tissue - and in these rare cases, emergency medical care is a must.

But most pill-based abortions can, in principle, take place at home without on-site medical supervision.

Right now, whether or not a person can legally use these medications to end a pregnancy depends on how long they’ve been pregnant and where they live.

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