The research could further complicate the polarized politics of abortion because the drug in the study is the key ingredient in a pill used for emergency contraception.
A new study suggests a possible alternative to the abortion pill mifepristone, a drug that continues to be a target of lawsuits and legislation from abortion opponents.
But the potential substitute could further complicate the politics of reproductive health because it is also the key ingredient in a contraceptive morning-after pill.
The new study, published Thursday in the journal NEJM Evidence, involved a drug called ulipristal acetate, the active ingredient in the prescription contraceptive Ella, one of two types of morning-after pills approved in the United States. (The other, Plan B One-Step, which does not require a prescription, contains a different drug and does not work in a way that would terminate a pregnancy, according to scientific evidence.)
In the study, 133 women who were up to nine weeks’ pregnant took twice the dose of the ulipristal acetate contained in Ella, followed by misoprostol, the second drug used in the typical medication abortion regimen. All but four of the women completed the termination of their pregnancies without further intervention, a 97 percent completion rate that is similar to the regimen using mifepristone. (The others finished the process with additional medication or a procedure.)
There were no serious complications, and the study concluded that using ulipristal acetate in the two-drug medication abortion regimen was safe.
Dr. Beverly Winikoff, the lead author of the study and the president of Gynuity Health Projects, a reproductive health research organization, said that after the Supreme Court overturned the national right to abortion in 2022, she began wondering about a possible role for ulipristal acetate, which has a similar chemical structure to mifepristone.