Research Provides Positive Evidence Supporting the Potential of Ulipristal for Early Medication Abortion
A study published today in NEJM Evidence provides positive evidence supporting the potential of ulipristal acetate in a combined regimen with misoprostol for safe and effective medication abortion.
The proof-of-concept study has given rise to breakthrough findings that warrant further investigation and provides a basis for future controlled trials comparing ulipristal with traditional medication abortion regimens. We are planning additional collaborative studies to gain further insights and explore broader applications of ulipristal in medication abortion.
Study Rationale
Gynuity Health Projects, a research and technical assistance organization, has been conducting exploratory clinical research into existing medicines that might offer an improvement to a misoprostol-only regimen and an alternative to a combined mifepristone-misoprostol regimen, the current recognized clinical standard for first trimester outpatient medication abortion.
An additional accessible and affordable method for medication abortion would be useful where access to mifepristone is restricted or its supply is interrupted and helpful in addressing unmet need and inequities worldwide.
Ulipristal has a similar chemical structure to mifepristone. It is widely available globally and is already established as a safe, effective method of emergency contraception within five days after unprotected intercourse.
Beverly Winikoff, the lead author of the paper and president of Gynuity Health Projects, said
“A major problem hindering use of medication abortion is availability. Increasing the number of methods and arsenal of options could have bold and transformative implications for potential users everywhere.”
About the Study
The two-stage study was implemented by Gynuity Health Projects together with the National Autonomous University of Mexico and Mexico City Health Secretariat and performed in the outpatient clinic of a public maternal hospital in Mexico City.
We first evaluated two different doses (90 and 60 mg) of oral ulipristal with misoprostol to see if one worked better and, because they showed similar efficacy and safety profiles, we then continued to evaluate the lower dose.
Participants with pregnancies of up to 63 days swallowed two 30 mg pills of ulipristal in-clinic and after a brief period of observation were discharged with four 200 mcg pills of misoprostol. They were counseled to self-administer the misoprostol 24 hours after the ulipristal, holding two pills in each cheek for 30 minutes before swallowing any remaining bits. Over one week later, they returned to the clinic to determine the status of the abortion and answer a series of questions about their experiences using the study medications and the acceptability of the regimen.
Study Results
Complete abortion occurred with the study regimen in 129 out of 133 (97%) participants, a success rate comparable to a mifepristone-misoprostol regimen. Among those for whom this regimen did not result in pregnancy termination, one had a completion with sharp curettage, two received manual vacuum aspiration, and one underwent a repeat medication abortion with misoprostol alone.
“The regimen shows a high success rate with minimal need for additional care, supporting ulipristal’s potential for medication abortion when combined with misoprostol.”, said Dr. María Laura García-Martinez, the principal investigator of the study in Mexico.
After ulipristal administration, side effects were rare. After taking misoprostol, the most common side effects were chills, diarrhea, and nausea; these side effects are transitory, easily managed, and often associated with misoprostol use. No serious adverse events were reported.
Overall satisfaction with the abortion process was high. Among the 133 participants questioned during the follow-up visit, 130 rated the treatment satisfactory or very satisfactory, 113 rated the pain level as acceptable or very acceptable, and 121 said they would recommend the study regimen.
Research Article
A proof-of-concept study of ulipristal acetate for early medication abortion Beverly Winikoff; Manuel Bousiéguez; Jorge Salmerón; Karina Robles-Rivera; Sonia Hernández-Salazar; Angélica Martínez-Huitrón; María Laura García-Martínez; Lucía Aguirre-Antonio; Ilana G. Dzuba; NEJM Evidence 2025.
Acknowledgements
This project was supported by the OPTions Initiative and the study was undertaken together with the National Autonomous University of Mexico and Mexico City Health Secretariat. We are grateful to the members of our Advisory Group and the Data and Safety Monitoring Board. We thank the study participants for contributing information that could help future users of medication abortion.
Media Inquiries
We are currently taking media inquiries by email -- pubinfo@gynuity.org
Also available in Spanish translation
Una investigación que proporciona evidencia positiva y que respalda el potencial del ulipristal para el aborto temprano con medicamentos
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