When to Use Emergency Contraception

Emergency contraception, commonly known as “the morning-after pill” or “Plan B”, should be taken within 72 hours of having unprotected sex. The pill releases hormones that prevent a woman from ovulating, the egg from fertilizing, or a fertilized egg from implanting, depending on where she is in her cycle. (Emergency contraception is not the same as an abortion pill—it will not work if a woman is already pregnant). If taken within 72 hours of unprotected sex, it is 89% effective. If taken within 24 hours of unprotected sex, it is 95% effective. While emergency contraception is a great option for preventing pregnancy in cases of emergency, it’s not as effective as primary forms of birth control, it doesn’t prevent STIs, and it’s a high-dose hormonal formulation that should not be taken frequently (that’s why they call it Plan B).

If you’ve had unprotected sex or are worried that your primary birth control method failed (aka, the condom broke or you’ve missed your pill a few days in a row), emergency contraception may be a good option for you. Just make sure to get the pill within the 72-hour window and take it as soon as possible to maximize efficacy. You’ll know your emergency contraception has worked when you get your next period.