- While there’s no limit to how many times you can take Plan B, that doesn’t mean you should treat it like a standard birth control pill that you take regularly.
- You only need one dose of Plan B for each episode of unprotected sex. Taking more than one dose won’t increase your chances of avoiding pregnancy.
- If you become nauseous and vomit shortly after taking Plan B, you should take another dose, since the pill didn’t have a chance to enter your system and do its job.
- If you had unprotected sex, again, a day or two after taking Plan B, you should consider taking another dose.
- This article was reviewed by Olivia P. Myrick, MD, who is a clinical assistant professor with the Department of Obstetrics and Gynecology at NYU Langone.
- Visit Insider’s homepage for more stories.
Plan B, commonly known as “the morning-after pill,” can prevent you from becoming pregnant. And while there’s no limit to how many times you can take Plan B, that doesn’t mean you should treat it like a standard birth control pill that you take regularly.
When you should take Plan B multiple times
Contrary to popular belief, it’s not an abortion pill and cannot terminate a preexisting pregnancy. Instead, you should only take Plan B in an emergency after you’ve had unprotected sex because either you didn’t use protection, your form of birth control failed during intercourse, or you missed a dose of your oral contraceptive pill that day.
If you take one dose of Plan B within 24 hours of unprotected sex, you have a 95% chance of preventing pregnancy because it interferes with your ovulation by either preventing or delaying it.
You only need one dose for each episode of unprotected sex. “Taking more than one dose of Plan B after one episode of unprotected sex is not going to make a difference in its effectiveness,” says Aparna Sridhar, MD, an OB-GYN at UCLA Health.
If you become nauseous and vomit shortly after taking Plan B, this is a case where you should take another dose, since the pill didn’t have the chance to really enter your system and do its job.
Additionally, let’s say you had unprotected sex again, a day or two after taking Plan B. In that case, you should consider taking another dose, since Plan B is really only meant to prevent pregnancy for that one instance of unprotected sex that’s already happened.
In other words, the Plan B you took for that first episode won’t cover you for the next one. According to the Plan B site’s FAQs, “If you have already used Plan B, it can be safely used again after another instance of unprotected sex or birth control failure.”
Plan B shouldn’t be your go-to form of birth control
Sridhar says the general consensus of doctors is that you should use some type of birth control the next time you have sex, so you won’t need to take Plan B again.
“The most important counseling I give my patients is to use condoms or another form of birth control for the rest of the cycle, because I don’t want them to assume they won’t get pregnant after taking one Plan B,” says Sridhar.
This being said, she also advises against taking Plan B multiple times a week. While, short-term side effects like headache, fatigue, and nausea can be common, it’s not technically medically harmful or dangerous to take multiple doses. But if you find yourself in this situation, you should strongly consider another type of birth control so you don’t find yourself relying on Plan B.
Plus, she says that using a different form of birth control properly will be more effective at preventing pregnancy than Plan B.
Taking Plan B multiple times won’t make you infertile
“While it is not recommended that Plan B be taken regularly, or as a replacement for traditional birth control, its effectiveness may not change with repeated use,” Sridhar says. In other words, if you do need to take Plan B multiple times, you won’t build up a tolerance to it like you can with some other medications.
“There may be transient changes in menstrual cycle bleeding patterns when it is used multiple times, but there is no evidence that emergency contraceptive pills have any long-term adverse effects on fertility,” Sridhar says.
So, if you’ve had unprotected sex within the last 72 hours and are nervous about an unwanted pregnancy, don’t hesitate to take Plan B, the sooner the better. You can rest assured that your body will be fine in the long run.
Related stories about birth control:
- How long it takes for condoms, birth control pills, and other types of birth control to expire
- You can take Plan B up to 120 hours after unprotected sex, but that’s not when it’s the most effective
- Birth control pills can help treat acne, but some types are better than others
- There are three types of birth control. Here’s how each type works and how well it prevents pregnancy
- You can get pregnant with an IUD but it’s extremely rare