Someone asked us:

Is it true that if you use the morning after pill a lot, it loses its effectiveness and eventually doesn’t work anymore?

No, this isn’t true. The morning-after pill won’t become less effective or stop working if you take it multiple times. Emergency contraception prevents pregnancy after unprotected sex, but it isn’t recommended as a regular form of birth control because it’s not as effective at preventing pregnancy as methods like the IUD, patch, pill, ring, or shot. It’s also not a very cost-effective form of birth control for regular use, and for some people it can come with some unpleasant side effects.

The only thing that can change the effectiveness of the morning after pill is how soon you take it after unprotected sex. It can be started up to 120 hours (five days) after unprotected sex. For most brands, the sooner you take it, the better it works. Typically, they reduce the risk of pregnancy by 89 percent when taken within 72 hours of unprotected sex. The only exception to this is the prescription brand Ella, which has the same effectiveness over the five days.

There are no long-term effects of emergency contraception, or any serious side effects. The only side effect of frequently using the morning after pill is an irregular menstrual cycle. Read more about emergency contraception.

- Nina at Planned Parenthood