mi·​fep·​ris·​tone | \ ˌmi-fə-ˈpri-ˌstōn How to pronounce mifepristone (audio) , mi-ˈfe-pri-ˌstōn \

Definition of mifepristone

: 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 One mifepristone manufacturer, GenBioPro, has already brought a lawsuit against Mississippi for its restrictions on the drug. Nicholas Florko, STAT, 28 June 2022 Misoprostol can be used alone if mifepristone is unavailable. Dominique Mosbergen, WSJ, 13 May 2022 The first pill, mifepristone, acts to block the body's ability to absorb progesterone, a hormone that allows the pregnancy to grow. Elizabeth Weise, USA TODAY, 7 May 2022 Notably, since 2000 a steady decline in abortions of all kinds has coincided with the availability of mifepristone. Joshua Cohen, Forbes, 2 June 2022 The process includes taking two medications: First the patient takes mifepristone, which blocks the hormone progesterone and stops the pregnancy. Angie Leventis Lourgos, Chicago Tribune, 23 May 2022 If mifepristone isn’t available, misoprostol can work alone. Megha Satyanarayana, Scientific American, 17 May 2022 The Food and Drug Administration approved the use of mifepristone for medical abortions in 2000. Morgan Sung, NBC News, 5 May 2022 One is done at home, with two pills, mifepristone and misoprostol. Susan Dunne, Hartford Courant, 15 May 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'mifepristone.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of mifepristone

1985, in the meaning defined above

History and Etymology for mifepristone

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

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Time Traveler for mifepristone

Time Traveler

The first known use of mifepristone was in 1985

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Dictionary Entries Near mifepristone

Mies van der Rohe



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Last Updated

30 Jun 2022

Cite this Entry

“Mifepristone.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mifepristone. Accessed 5 Jul. 2022.

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More Definitions for mifepristone


mi·​fep·​ris·​tone | \ ˌmi-fə-ˈpris-ˌtōn How to pronounce mifepristone (audio) , mi-ˈfep-ri-ˌstōn How to pronounce mifepristone (audio) \

Medical Definition of mifepristone

: 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

Britannica.com: Encyclopedia article about mifepristone


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