How a medication abortion, also known as an 'abortion pill,' works

While the fate of mifepristone, one of two drugs used for medication abortions, is in the hands of the US Supreme Court, the drug continues to be available in states where abortion is legal.

"While many women obtain medication abortion from a clinic or their OB-GYN, others obtain the pills on their own to self-induce or self-manage their abortion," said Dr. Daniel Grossman, a professor of obstetrics, gynecology and reproductive sciences at the University of California, San Francisco.

"A growing body of research indicates that self-managed abortion is safe and effective," he said.

Mifepristone blocks the hormone progesterone, which is needed for a pregnancy to continue. The drug is approved to end a pregnancy through 10 weeks' gestation, which is "70 days or less since the first day of the last menstrual period," according to the FDA.

In a medication abortion, a second drug, misoprostol, is taken within the next 24 to 48 hours. Misoprostol causes the uterus to contract, creating cramping and bleeding. Approved for use in other conditions, such as preventing stomach ulcers, the drug has been available at pharmacies for decades.

Together, the two drugs are commonly known as the "abortion pill," which is now used in more than half of the abortions in the United States, according to the Guttmacher Institute, a research group that supports abortion rights.

"Some people do this because they cannot access a clinic - particularly in states with legal restrictions on abortion - or because they have a preference for self-care," said Grossman, who is also the director of Advancing New Standards in Reproductive Health, a research group that evaluates the pros and cons of reproductive health policies and publishes studies on how abortion affects a woman's health.