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The Emergency Contraception Website - Your website for the "Morning After"

Answers to Frequently Asked Questions About...

How to Use Emergency Contraception

What if I take the second dose of emergency contraceptive pills late?

The instructions for Levonorgestrel Tablets and other 2-pill progestin-only emergency contraceptive products say that you should take two doses 12 hours apart (that’s one pill followed 12 hours later by another pill.) However, research shows that progestin-only emergency contraceptive pills (also called "morning after pills" or "day after pills") are equally effective if you take the two doses at the same time, take them 12 hours apart as recommended, or wait as long as 24 hours to take the second dose. That’s why, in many countries, the instructions for specially packaged progestin-only emergency contraceptive pills (like Postinor or NorLevo) say to take both pills at once.


Plan B One-Step, Take Action, Next Choice One Dose and My Way are single-pill products that contain the same amount of hormones found in two Levonorgestrel pills; if you're using Plan B One-Step, Next Choice One Dose or My Way , you simply take the pill as soon as possible after sex. Similarly, ella (ulipristal acetate) is just one pill that you take as soon as possible after sex (in clinical studies, the effectiveness of ella doesn't decline over a 5-day period, but for each individual woman, what's important is where she is in her own cycle; emergency contraceptive pills don't appear to work after ovulation has occurred).

Research about “combined” emergency contraceptive pills (those are pills containing both estrogen and progestin, such as regular birth control pills used in different doses as EC), in contrast, has focused on taking the two doses 12 hours apart. Even so, taking the second dose a little early or a little late (like a difference of two hours) will probably not make a difference in how effective the pills are.

Click here for more detailed instructions for using ella, Plan B One-Step, Next Choice One Dose, My Way, Levonorgestrel Tablets, or daily birth control pills for emergency contraception.

A thorough and up-to-date academic review of research about how and when to take emergency contraceptive pills, as well as other medical and social science literature about emergency contraception is available here .


This website is operated by the Office of Population Research at Princeton University and by the Association of Reproductive Health Professionals and has no connection with any pharmaceutical company or for-profit organization.

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