for females ages 18 years and up (full criteria)
Healthy Volunteers
healthy people welcome
at San Francisco, California
study started
estimated completion
Principal Investigator
by Ushma Upadhyay, PhD, MPH
Photo of Ushma Upadhyay
Ushma Upadhyay



The Missed Period Pill Study is a prospective observational study among people who decide to use misoprostol alone for menstrual regulation.

Official Title

Assessing the Acceptability of Using Misoprostol Alone for Menstrual Regulation


As the number of state laws restricting access to abortion increases across the country, more creative methods are needed to support individuals in achieving their reproductive goals. Misoprostol alone for people who suspect, but have not confirmed pregnancy, has the potential to fulfill this growing need. The goal of this research study is to test a traditional but underutilized framework of menstrual regulation for pregnancy loss, to "bring back" a period when it is missed. This study will aim to recruit 100 patients who have a missed period to address research questions that focus on the feasibility and acceptability of using misoprostol alone for menstrual regulation. The study will require 2 study visits. First study visit: A urine sample will be collected which will later undergo pregnancy testing. Participants will be given misoprostol along with instructions and information on what to expect. The participant will be required to return to the clinic 4 weeks later to provide another urine sample. The participant will not know the results of the first visit's pregnancy test at any point. The clinic staff member administering the participant's care will not know of the pregnancy test result while the participant is at the clinic. Second study visit: The second pregnancy test that will be conducted at the follow-up visit will inform the participant and research staff whether the treatment was successful. The participant will then be asked to answer questions on an online survey about their experience using misoprostol. A variety of clinical and social science measures will be collected to assess the feasibility and acceptability of this traditional concept of menstrual regulation utilizing uterine evacuation with medications.


Menstrual Regulation Menstrual Irregularity late period missed period mensturation Menstruation Disturbances Misoprostol


You can join if…

Open to females ages 18 years and up

  • Be 18 years old or older
  • Read and speak English
  • Know the date of their last menstrual period within 2 days
  • Have a period that is late by up to 14 days
  • Have had regular periods in the last 4-6 months
  • Does not want to be pregnant; understand that if they are pregnant, the pills will end their pregnancy
  • Be willing to have an abortion if the missed period pill does not work, and informed of potential for birth defects in any ongoing pregnancy
  • Does not want to verify pregnancy status
  • Does not have risk factors for ectopic pregnancy (history of ectopic pregnancy, recent vaginal bleeding or spotting, pelvic pain on one side, prior permanent contraception, or other tubal surgery)
  • Does not have an IUD
  • Does not currently use a contraceptive implant or injectable
  • Does not have contraindications to misoprostol
  • Agree to participate in the follow up visit/call

You CAN'T join if...

  • Participants who have contraindications to misoprostol
  • Unknown date of last menstrual period
  • Risk factors for ectopic pregnancy (history of ectopic pregnancy, recent vaginal bleeding or spotting, pelvic pain on one side, prior permanent contraception, or other tubal surgery)
  • Irregular menses or any other condition that in the opinion of the Principal Investigator would compromise participant safety.


  • University of California, San Francisco (Mission District)
    San Francisco California 94110 United States

Lead Scientist at UCSF

  • Ushma Upadhyay, PhD, MPH
    Associate Professor, Ob/Gyn, Reproductive Sciences. Authored (or co-authored) 85 research publications. Research interests: sexual and reproductive health · women's empowerment · women's reproductive autonomy · relationship power · gender-based power · U.S. abortion restrictions · abortion procedures · complications of abortion · medication abortion · telemedicine for abortion


not yet accepting patients
Start Date
Completion Date
University of California, San Francisco
Missed Period Pill Study Enrollment Website
Phase 4
Study Type
Last Updated