For Healthcare Professionals > Plan B One‑Step® How Plan B Works Plan B Side Effects Taking Plan B Countdown Calculator Find a Store How to Save 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. What Plan B isn’t: Not regular birth control Since Plan B only stays in your body for a short amount of time, it’s not meant to be used as a regular birth control method. You can and should immediately continue taking your regular birth control—or start using one—after taking Plan B. Not an abortion pill It won’t affect an existing pregnancy. Won’t protect against HIV/AIDS or other STDs Plan B will help prevent pregnancy before it starts, but it won’t prevent any sexually transmitted diseases. You should always use a barrier method, like condoms, to prevent STDs. See when to take Plan B Plan B is safe and effective Plan B shouldn’t be used as a regular form of birth control, as it only stays in your body for a short amount of time and works to help prevent pregnancy after only one instance of unprotected sex. If you find that you are using emergency contraception frequently, talk to your doctor about finding a regular birth control method that’s right for you—as regular birth control pills are more effective. Keep in mind: Plan B won’t interfere with your regular birth control methods or make them any less effective. See common side effects Still have questions? We’ve got you covered. See all FAQs Contact Us FAQs News & Media Resources Privacy Notice Terms of Use Site Map Instagram Facebook YouTube Twitter Use as directed. Plan B One‑Step is a registered trademark of Foundation Consumer Healthcare. © 2020 Foundation Consumer Healthcare. This site is intended for US audiences only.