Today mifepristone is often used in combination with another drug, misoprostol, and together the pair are more than 95 percent effective at ending a pregnancy when taken during the first 50 days. While mifepristone blocks the hormone progesterone—which regulates the lining of the uterus and the maternal immune system, allowing pregnancy to take place—misoprostol stimulates the uterus to expel the pregnancy.
In the 34 years since mifepristone’s tumultuous introduction in France, more than 60 countries have approved it, including the US in 2000 and the UK in 1991 (though it didn’t legally become available in Northern Ireland until abortion was decriminalized in 2019). However, mifepristone remains subject to rules governing its use in most places.
The emergence of pills that could induce an abortion was “absolutely revolutionary,” says Clare Murphy, CEO of the British Pregnancy Advisory Service charity. Yet even now, many people do not know that abortion pills—which are completely different from emergency contraception—exist.
Medical professionals and health experts who spoke to WIRED say these drugs are extremely safe and have made the process of self-terminating a pregnancy (which is illegal but still practiced in many places) much safer than it once was.