mi·​fep·​ris·​tone ˌmi-fə-ˈpri-ˌstōn How to pronounce mifepristone (audio)
: a drug C29H35NO2 taken orally to induce abortion especially early in pregnancy by blocking the body's use of progesterone

called also RU-486

Examples of mifepristone in a Sentence

Recent Examples on the Web Mar 26, 6:23 AM What is mifepristone at center of Supreme Court battle? Alexandra Hutzler, ABC News, 26 Mar. 2024 Of course, if the Supreme Court upholds the appeals court decision, the most immediate impact would be to mifepristone itself. Meg Tirrell, CNN, 26 Mar. 2024 More than half of American women who choose to terminate a pregnancy do so with a two-drug combination that includes mifepristone — the drug at the heart of this case. Suzanne Nuyen, NPR, 26 Mar. 2024 Earlier this month, his administration celebrated a decision by CVS and Walgreens agreeing to fill prescriptions for mifepristone in certain states. Daniel Desrochers, Kansas City Star, 26 Mar. 2024 In August, a panel of federal appeals judges in New Orleans limited his ruling, determining that mifepristone should remain legal but imposing significant restrictions on access. Abbie Vansickle, New York Times, 26 Mar. 2024 Here’s a closer look at the safety of mifepristone. Karen Kaplan, Los Angeles Times, 26 Mar. 2024 At the center of the legal battle is the pill mifepristone, which is taken along with another drug to terminate an early pregnancy. Melissa Quinn, CBS News, 26 Mar. 2024 During Tuesday’s arguments, a major line of questioning from justices was about ER visits following mifepristone use and whether the FDA’s loosening of regulations on the drug in recent years has resulted in an increase in these visits. Emily Mullin, WIRED, 26 Mar. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'mifepristone.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


perhaps from amino + fe- (alteration of phen-) + pri- (alteration of prop-) + estradiol + -one

First Known Use

1985, in the meaning defined above

Time Traveler
The first known use of mifepristone was in 1985

Dictionary Entries Near mifepristone

Cite this Entry

“Mifepristone.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mifepristone. Accessed 18 Apr. 2024.

Medical Definition


mi·​fep·​ris·​tone ˌmi-fə-ˈpris-ˌtōn How to pronounce mifepristone (audio) mi-ˈfep-ri-ˌstōn How to pronounce mifepristone (audio)
: a drug C29H35NO2 taken orally to induce abortion especially early in pregnancy by blocking the body's use of progesterone

called also RU-486

More from Merriam-Webster on mifepristone

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