mifepristone

American  

[mif-uh-pris-tohn] / ˌmɪf əˈprɪs toʊn /

noun

1. an antigestational drug, C 29 H 35 NO 2 , that prevents a fertilized egg from attaching to the uterine wall by blocking the action of progesterone.

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mifepristone British  

/ mɪˈfɛprɪˌstəʊn /

noun

1. an antiprogestogenic steroid, used in the medical termination of pregnancy. Formula: C 29 H 35 NO 2

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Etymology

Origin of mifepristone

1985–90; probably alteration of (a)mi(no)phe(nol) + pr(opyl) + est(radiol) + -one

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Example Sentences

See Examples For:

mifepristone

There are any number of unknowns, but one thing is clear: A majority of the justices ruled that mifepristone access should remain unchanged during litigation in the case.

From Slate ● Sep. 16, 2026

She said proposals to test wastewater for mifepristone raise concerns about how such monitoring data could eventually be used and whether it could increase scrutiny of people who obtain medication abortions.

From Salon ● Jul. 6, 2026

Nathan Donley, the environmental health science director at the Center for Biological Diversity, pointed out that mifepristone is used by a small fraction of the population and is typically taken as a one-time dose.

From Salon ● Jul. 6, 2026

Former FDA Commissioner Marty Makary, ousted last month, had promised lawmakers he would launch a mifepristone study but told others in the administration that he needed new data systems for the effort.

From The Wall Street Journal ● Jun. 5, 2026

On this week’s Amicus, Dahlia Lithwick and Mark Joseph Stern dive into the legal battle over mifepristone, the medication that can be used for abortion care.

From Slate ● May 21, 2026

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