Mifepristone is a drug used as part of a two-drug regimen to end a pregnancy without surgery.
The combination of mifepristone and misoprostol causes a complete abortion in more than 99% of patients.
Mifepristone blocks a hormone called progesterone that is necessary for a pregnancy to continue, while misoprostol brings on uterine contractions.
Medication abortion is as safe as traditional abortion procedures administered by a doctor in a clinic.
Medication abortion has low rates of adverse events, and patients are generally satisfied with it.
Misoprostol can also end a pregnancy when used alone, and is also used to treat ulcers.
The FDA has approved medication abortion for up to 10 weeks of pregnancy, while WHO guidelines say it can be used up to 12 weeks at home.
About half of people who get legal abortions in the US use medication abortion.
Medication abortion is also used illicitly by those who live in a place that restricts legal abortion or by those who can't reach a clinic.
The US abortion rate may be higher than officially reported due to people ordering pills online.