RisksBy Mayo Clinic Staff
Emergency contraception is an effective option for preventing pregnancy after unprotected sex, but it isn't as effective as other methods of contraception and isn't recommended for routine use. Also, the morning-after pill can fail even with correct use, and it offers no protection against sexually transmitted infections.
The morning-after pill isn't appropriate for everyone. Don't take a morning-after pill if:
- You're allergic to any component of the morning-after pill
- You're taking certain medications that may decrease the effectiveness of the morning-after pill, such as barbiturates or St. John's wort
- You know you're already pregnant
Also, if you're overweight or obese, there's some indication that the morning-after pill won't be as effective in preventing pregnancy as it is for normal-weight women.
In addition, make sure you're not pregnant before using ulipristal. The effects of ulipristal on a developing baby are unknown. However, if you're already pregnant when you take levonorgestrel, the treatment will simply be ineffective and won't harm the developing baby. Also, if you're breast-feeding, ulipristal isn't recommended.
Side effects of the morning-after pill typically last only a few days and may include:
April 14, 2015
- Nausea or vomiting
- Breast tenderness
- Bleeding between periods or heavier menstrual bleeding
- Lower abdominal pain or cramps
- Zieman M. Emergency contraception. http://www.uptodate.com/home. Accessed March 4, 2015.
- FDA approves Plan B One-Step emergency contraceptive for use without a prescription for all women of child-bearing potential. U.S. Food and Drug Administration. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm358082.htm. Accessed March 4, 2015.
- Shohel M, et al. A systematic review of effectiveness and safety of different regimens of levonorgestrel oral tablets for emergency contraception. BioMed Central Women's Health. 2014;14:54.
- Ella (prescribing information). Parsippany, N.J.: Watson Pharma Inc.; 2012. http://pi.watson.com/data_stream.asp?product_group=1699&p=pi&language=E. Accessed March 4, 2015.
- Plan B One-Step (prescribing information). Pomona, N.Y.: Duramed Pharmaceuticals Inc.; 2009. http://www.planbonestep.com/pdf/PlanBOneStepFullProductInformation.pdf. Accessed March 4, 2015.
- Koyama A, et al. Emerging options for emergency contraception. Clinical Medical Insights: Reproductive Health. 2013;7;23.