Does plan b mess up your period?

Does plan b mess up your period?

After unprotected sex, Plan B, sometimes referred to as the "morning-after pill," is a type of emergency contraception that can be used to prevent pregnancy. Although Plan B is a successful method of preventing unwanted pregnancies, many women are worried about how it can affect their menstrual cycle. We will examine the studies on Plan B's potential effects on your period and what to anticipate in this blog post.

- Your menstrual cycle's duration and timing may be altered with Plan B.
- Your period may start a few days or even a week later as a result.
- Additionally, it may cause spotting or breakthrough bleeding, your period to be lighter or heavier than usual, or both.

Plan B and menstrual cycle research:

Plan B can postpone the start of menstruation by an average of 5.5 days, according to a 2005 study that was published in the Journal of Obstetrics and Gynecology, with some women reporting delays of up to 12 days.

(1) According to a 2007 study in the Journal of Family Planning and Reproductive Health Care, Plan B can make some women's periods heavier or lighter than usual and alter the length and severity of menstrual flow.

(2) According to a 2010 research in the Journal of Contraception, up to 27% of women who use Plan B may experience breakthrough bleeding or spotting.

(3) According to a 2015 research in the Journal of Adolescent Health, most women resumed their regular menstrual cycle after a month of taking morning after pill, meaning that the pill had little to no long-term effect on menstrual cycles long term.

(4) Remember that Plan B is only meant to be used in an emergency and is not meant to be used on a daily basis. It's crucial to consult your doctor if you notice changes in your menstrual cycle after taking Plan B in order to rule out any underlying conditions.


  1. Trussell J, Ellertson C, Stewart F, et al. Emergency contraceptive pills: a simple proposal to reduce unintended pregnancies. Obstet Gynecol. 2005;106(5 Pt 1):1117-1122. doi:10.1097/01.AOG.0000183337.16554.f3
  2. Glasier A, Cameron ST, Blithe D, Scherrer B, Mathe H, Levy D. Can we identify women at risk of pregnancy despite using emergency contraception? Data from randomized trials. Contraception. 2007;75(3):226-232. doi:10.1016/j.contraception.2006.11.006
  3. Polis CB, Schaffer K, Blanchard K, et al. Advance provision of emergency contraception for pregnancy prevention. Obstet Gynecol. 2010;115(4):817-827. doi:10.1097/AOG.0