Understanding Missed Period Pills
You may have seen some buzz about “missed period pills” online and might be wondering, What are they? and Do they actually work?
How do they work?
Missed Period Pills are a combination of pills taken by women who are concerned about the possibility of pregnancy due to their period being late. The medication combination will either immediately bring on your period, or, if you have conceived since your last period, will induce an abortion.
The regimen includes mifepristone, a medication used to disrupt the flow of progesterone to the uterus (called a progesterone antagonist), and misoprostol, which causes contractions and causes the lining of the uterus and its contents to pass through the vagina.
The practice of taking these medications before pregnancy is confirmed is also called menstrual regulation, period pills, pushing your period, uterine evacuation medication, or bringing down your period.
The Difference Between the Abortion Pill and Missed Period Pills
Is there a difference between the two?
In actuality, no. While they are called two different things, Missed Period Pills (Misoprostol and Mifepristone), are the same two medications that make up a medication abortion (also called Plan C or RU-486), and are taken in the same dosages in both cases. The practice of pushing or bringing down a period is actually taking medication abortion pills without a pregnancy test, so the user doesn’t know if they had an abortion or not.
The only difference between the abortion pills and period pills is the knowledge of whether or not the woman is actually pregnant. Whether the regimen is called “missed period pills” or “self-managed abortion,” if the user is pregnant, it will end the pregnancy. If the user is not pregnant, it will force her period to start.
What’s the Difference Between Menstrual Regulation and Plan B?
While missed period pills and Plan C are the same, Plan B is designed to delay ovulation and thus avoid pregnancy. This medication is taken as soon as possible after unprotected intercourse and will not end a pregnancy that has already implanted.
Concerns About Safety and Side Effects
The ingredients and dosage of both self-managed abortions and period pills are the same, and therefore the symptoms, risks, and outcomes are also the same whether the user is taking them with the mindset of avoiding pregnancy or of ending pregnancy.
Mifepristone (Missed Period Pills or Mifeprex) is not recommended for patients who:
- Are on blood thinning medications
- Are on one of the medications listed as a contraindication
- Have a history of adrenal problems, heart problems, circulation issues, blood clotting issues, or kidney or liver disease
- Are concerned about an ectopic pregnancy
It is important to know how long it has been since your last menstrual period before taking mifepristone. According to the FDA, it should not be taken past 10 weeks of pregnancy, so if you aren’t certain of your last menstrual period, it is important to have an ultrasound to confirm your dating prior to taking this medication as risks increase significantly with a medical abortion the further along you are in pregnancy.
If you have not ruled out the possibility of an ectopic pregnancy with ultrasound, do not take mifepristone. The medication targets the uterus, meaning it will not affect a pregnancy that is developing outside of the uterus. Should an ectopic pregnancy continue to develop, serious side effects and, rarely, death can occur.
FDA Does Not Recommend Purchasing This Medication Online
The FDA does not recommend the purchase of mifepristone and misoprostol online, as this method bypasses the safeguards the FDA has put in place to protect your health. The FDA does not have oversight over medications that are dispensed online (especially from overseas) and therefore cannot ensure the safety or efficacy of these medications.
Side Effects of the Missed Period Pill
Common Side Effects
The combination of the two medications (whether taken with a confirmation of pregnancy or not), will cause bleeding and contractions to empty the contents of your uterus. Bleeding lasts for a median of 12 days but can last anywhere from 4 and 43 days.
Moderate reactions are reported to be nausea, abdominal pain, fever, vomiting, fatigue, headache, diarrhea, dizziness, GERD, insomnia, pelvic pain, chills, and menstrual irregularity. Bleeding can last between 2-8 weeks. Side effects are different from individual to individual.
Serious Side Effects
In a UK study of women who had taken medication abortion pills, 9.3% of patients reported symptoms of a potentially serious complication. Recent data from a US review of medicaid codes reported a complication rate of 10.93%.
The Mifepristone REMS (Risk Evaluation and Mitigation Strategy) required by the FDA reports serious risks such as heavy bleeding, infection, and ectopic pregnancy complications. It advises that if users experience a fever of 100.4 or higher, severe abdominal pain, heavy bleeding, weakness, nausea, vomiting, or diarrhea for more than 24 hours after taking the medication, they should call their prescribing physician right away.
Should you need medical help after taking these medications, be sure to bring the medication information that came with the prescription with you to ensure that you get the correct treatment. In the US you will not be prosecuted for seeking help after having a medication abortion.
Incomplete Abortion
Even if you took the medications as a missed period pill, in the case that you were pregnant, prolonged bleeding can be a sign of incomplete abortion or other complications. In this case, a D&C may be needed to empty the uterus and prevent infection. Medication abortions are incomplete between 5.3% – 7% of the time.
Seeking Support and Guidance
At Alpha Center, we understand that the possibility of an unplanned pregnancy can be overwhelming. Our nurses and intake specialists are trained to give you the information you need to make an informed decision without judgment.
What If I’m Not Pregnant?
Before you look to obtain missed period pills, consider whether or not there could be other reasons for a late period. Hormone changes, birth control, weight fluctuations, chronic illness, and or other possible stressors are all possible reasons for menstrual irregularities.
Informed Consent and Missed Period Pills
If you’re worried about pregnancy, it may be better for your overall health to first find out whether or not you are actually pregnant (in case you don’t need to take the pills at all), and, if you are, to consider your options and receive an ultrasound and STI test to ensure that you have all the information you need to make an informed decision.
During a pre-abortion screening at Alpha Center you will take a pregnancy test, meet with a nurse to discuss your medical history, and receive a limited ultrasound to determine how far along you are, whether the pregnancy is viable, and whether it appears to be in the correct location. We will also offer limited STI screening at the appointment.
If you are concerned about a potential pregnancy, call Alpha Center at 970.239.2272 or click on the Chat Now Button on the corner of your screen.
Disclaimer: Alpha Center does not perform or refer for abortions or missed period pills. This means we have no financial interest in your pregnancy outcome. All of our services are free to the community because of the generosity of donors.
Authored by Kristen Long for Alpha Center and reviewed by Meghan Downing, RN, Nurse Manager.
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Meta Description:
Discover the essential facts about missed period pills and what you need to know before you take them, and what should be included in a pre-abortion screening.
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References
- Interest in period pills in the United States: A nationally representative survey, 2021–2022
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- Aiken, A. R. A., Digol, I., Trussell, J., & Gomperts, R. (2017, April 17). Self reported outcomes and adverse events after medical abortion through online telemedicine: population based study in the Republic of Ireland and Northern Ireland. thebmj. Retrieved August 9, 2025, from https://www.bmj.com/content/357/bmj.j2011
- Autry, B. M., & Wadhwa, R. (2024, February 28). Mifepristone – StatPearls. NCBI. Retrieved August 11, 2025, from https://www.ncbi.nlm.nih.gov/books/NBK557612/
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- Hall, B., & Anderson, R. T. (2025, April 28). The Abortion Pill Harms Women: Insurance Data Reveals One in Ten Patients Experiences a Serious Adverse Event. Ethics & Public Policy Center. Retrieved August 11, 2025, from https://eppc.org/publication/insurance-data-reveals-one-in-ten-patients-experiences-a-serious-adverse-event/
- Rodger, M. W., & Baird, D. T. (1987, December 19). Induction of therapeutic abortion in early pregnancy with mifepristone in combination with prostaglandin pessary. National Library of Medicine. Retrieved August 8, 2025, from https://pubmed.ncbi.nlm.nih.gov/2891991/
- Missed your period but not pregnant? 7 possible causes. (2024, January 3). UCLA Health. Retrieved August 11, 2025, from https://www.uclahealth.org/news/article/missed-your-period-not-pregnant-7-possible-causes-2
- Dilation and curettage (D&C). (2023, November 7). Mayo Clinic. Retrieved August 11, 2025, from https://www.mayoclinic.org/tests-procedures/dilation-and-curettage/about/pac-20384910