How Plan B Works

If you’re going to take Plan B, you want to know how it works

So let’s start with the facts.

What Plan B is:

  • Emergency contraception that works by temporarily delaying ovulation

    Similar to birth control pills, Plan B works by temporarily delaying the release of an egg from the ovary, so there’s no egg to meet the sperm. No egg, no fertilization, no pregnancy.

  • A backup plan that won’t impact your ability to get pregnant later on

    Not ready right now, but think you might want to get pregnant in the future? Taking Plan B now to help prevent pregnancy after unprotected sex won’t hurt your ability to get pregnant in the future.

  • Available for purchase at all major retail stores—no ID or Rx required

    You can find Plan B yourself in the family planning aisle. There’s no ID or Rx needed, and no age requirement to purchase.

Plan B is not an abortion pill. It won’t harm an existing pregnancy.

How does Plan B fit into your birth control regimen?

Birth control (or contraception) is any method, medicine, or device used to prevent a pregnancy before it starts. There are many different types of birth control. Some work better than others at preventing pregnancy and no method is 100% effective. But your chances of getting pregnant are lower if you use a more effective method.

  • Primary methods of birth control are meant to be used before sex to prevent a pregnancy. These methods can range from things like condoms (which can be found right at the store without a prescription) to birth control pills or IUDs (which need to be prescribed by your doctor).

  • Emergency contraception (like Plan B) is a form of birth control that is meant to be used if your primary method failed (like a condom broke or you missed pills) or you forgot to use primary birth control. Plan B is used to help prevent pregnancy after sex and must be taken within 72‑hours after unprotected sex or if your primary birth control failed. The sooner you take it, the better it will work. It is not meant to be used as a regular form of birth control because it is not as effective.

If you find that you are using Plan B frequently, talk to your doctor about finding a primary birth control method (a “plan A” method) that is right for you.

Keep in mind:

Plan B won’t interfere with your regular birth control methods or make them any less effective. So, you can continue your regular birth control right away—or start one, if you don’t have a regular method.

Still have questions?

We’ve got you covered.