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What are the side effects of emergency contraceptive pills?
Emergency contraceptive pills (also known as "morning after pills" or "day after pills") have no long-term or serious side effects, and emergency contraception is safe for almost every woman to use. In general, progestin-only (like Plan B One-Step, Next Choice One Dose or Take Action) and ulipristal acetate (ella) emergency contraceptive pills have fewer side effects than combined emergency contraceptive pills (pills containing both estrogen and progestin, such as regular birth control pills used as EC).
You might find yourself feeling queasy and some women throw up after taking emergency contraceptive pills. You might also get a headache, feel tired or dizzy, have some lower abdominal pain, or find your breasts are more tender than usual. If you do feel this way, it should stop within a day or two. Some women also find that the pills cause unexpected bleeding; this is not dangerous and should clear up by the time you have your next period. The pills might also cause your next period to come early or late. (For more information about how emergency contraception might affect your monthly cycle, click here).
A study comparing levonorgestrel (such as Plan B One-Step, Next Choice One Dose or Take Action) and ulipristal acetate (ella) showed generally similar side effects for the two medications1. About 20% of women in each group experienced headaches following EC treatment, 13-14% experienced painful menstruation, and 11-12% experienced nausea. Women taking ulipristal acetate had their next period on average 2.1 days later than expected, while women taking levonorgestrel began their next period 1.2 days earlier than expected, but the duration of periods was not affected.
To prevent nausea and vomiting, you can take the non-prescription anti-nausea medicine meclizine (also sold under the brand names Dramamine II or Bonine). Research shows that taking two 25 mg tablets 1 hour before using combined emergency contraceptive pills reduces the risk of nausea by 27% and vomiting by 64%, but this drug doubles your chances of feeling drowsy (to about 30%). If you happen to throw up within 1 hour of taking a dose of either type of emergency contraceptive pills, some health care providers recommend repeating that dose just in case your body didn’t have a chance to absorb all of the medication.
For a thorough and up-to-date academic review of the medical and social science literature on emergency contraception, including side effects, click here .
1 Glasier A, Cameron S, Fine P et al. Ulipristal acetate versus levonorgestrel for emergency contraception: a randomized non-inferiority trial and meta-analysis. The Lancet 2010; 375:555-562.