Progesterone use to reverse the effects of mifepristone

Ann Pharmacother. 2012 Dec;46(12):e36. doi: 10.1345/aph.1R252. Epub 2012 Nov 27.


Objective: To present a series of cases demonstrating successful reversal of mifepristone effects in women who chose to reverse the medical abortion process.

Case reports: Four of 6 women who took mifepristone were able to carry their pregnancies to term after receiving intramuscular progesterone 200 mg.

Discussion: Mifepristone has been available in the US since 2000. By 2008, approximately 25% of abortions prior to 9 weeks were accomplished with mifepristone. Some women who take mifepristone wish to reverse the medical abortion process. Progesterone competes with mifepristone for the progesterone receptor and may reverse the effects of mifepristone. A PubMed literature search from 1996 to May 2012 did not reveal any trials or case studies evaluating the efficacy of progesterone use to reverse the effects of mifepristone.

Conclusions: Health care professionals should be aware of the possible use of progesterone to reverse mifepristone in women who have begun the medical abortion process by taking mifepristone and then change their minds.

Publication types

  • Case Reports

MeSH terms

  • Abortifacient Agents, Steroidal / administration & dosage
  • Abortifacient Agents, Steroidal / antagonists & inhibitors*
  • Abortion, Induced / methods*
  • Adult
  • Female
  • Humans
  • Injections, Intramuscular
  • Mifepristone / administration & dosage
  • Mifepristone / antagonists & inhibitors*
  • Pregnancy
  • Pregnancy Outcome
  • Progesterone / pharmacology*
  • Receptors, Progesterone / drug effects
  • Receptors, Progesterone / metabolism
  • Young Adult


  • Abortifacient Agents, Steroidal
  • Receptors, Progesterone
  • Mifepristone
  • Progesterone