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Plan B Myths: Emergency Contraception Facts

Hey Jane debunks common Plan B myths: no 3-time limit, no weight gain, no fertility impact. Learn the facts about emergency contraception, weight thresholds, and how to get Plan B or Ella online.

Although it goes by many names—from “the morning-after pill” to Plan B—emergency contraception does one very important thing: helps prevent a pregnancy from occurring, following unprotected penis-in-vagina sex or after a birth control method fails (for example, if a condom breaks). There’s no need to wait until an “emergency” to get the facts about emergency contraception. Here’s what you need to know about this safe, effective reproductive health option. 

Are there different types of emergency contraception?

Yes. There are two common types of emergency contraceptive pills, levonorgestrel, or Plan B, and ulipristal acetate, also known as Ella.

Ella vs. Plan B

Some differences between these two medications include:

Ella Plan B
When it works Ella can be taken up to 5 days (120 hours) after unprotected intercourse. Plan B should be taken within 3 days (72 hours). For both options, it's most effective to take the pill as soon as possible.
Effectiveness 95% effective when used as directed. 89% effective with proper intended use.
Weight considerations* Works best in those weighing less than 195 pounds. Most effective in people weighing 165 pounds or less.
How to get it Requires a prescription. Consider using an online service like Hey Jane to get a prescription in advance — you can keep it at home for a future emergency. Available over-the-counter at most drug stores. No prescription required, though insurance can cover the cost if you have one.
Shelf life 3 years 4 years
Resuming oral contraceptives Wait at least 5 days after taking Ella before starting or restarting a daily oral birth control pill, as the ingredients may make Ella less effective. You can take birth control pills as soon as the next day.

*Some studies show a higher rate of unintended pregnancy in people with a higher BMI. That being said, emergency contraceptive pills do not have a weight restriction, may still help to prevent pregnancy, and are safe no matter your BMI.

Can an IUD be used as emergency contraception?

The most effective form of emergency contraception is also a long-term birth control method! When used within 5 days of unprotected intercourse, a copper-containing IUD, like the ParaGard, is 99% effective in preventing an undesired pregnancy. It also protects against future pregnancies for up to 12 years. While the copper IUD has been shown to be most effective, recent studies suggest hormonal IUDs might also be used as emergency contraception. Because inserting an IUD requires an in-office visit, we recommend that you talk to your health care provider about which option is best for you.

How long after sex can you take the morning-after pill?

Emergency contraception is effective 72 to 120 hours after intercourse, depending on the method used. For some brands, it’s more effective the sooner you take it; we recommend talking to your prescriber or reading through the instructions that came with your emergency contraception to get a better idea of the timeline. Learn more about how to prevent pregnancy after sex here.

Can you use multiple birth control pills instead of Plan B?

Some daily oral birth control pills can be used as emergency contraception by taking 2-5 tablets at once. Because the dosage varies widely depending on your birth control, contact your prescriber about the best dosage for you.

While this option can be helpful for people in a pinch who can’t access other emergency contraception methods quickly, it does mean that you’ll be short on the number of birth control pills you have available for the rest of the month. If that’s the case for you, using a backup method like condoms might be a good idea.

Is there a limit to how many times you can take Plan B?

Plan B is safe to take as many times as needed. Read more here.

Peace of mind starts with a backup plan
Woman with dark curly hair in black shirt looking at phone and medication blister packWoman with dark curly hair in black shirt looking at phone and medication blister pack

Does Plan B make you gain weight?

There’s no evidence to suggest that taking Plan B causes weight gain. While some hormonal contraceptives have been linked to slight changes in weight due to fluid retention or appetite shifts, Plan B is a single-dose emergency contraceptive and doesn’t stay in your system long enough to affect your weight. Rest assured, Plan B is a safe and effective way to prevent pregnancy after unprotected sex, without long-term impacts on your weight.

How much does Plan B cost?

Plan B can cost anywhere between $10 to $50 over the counter and varies based on whether or not you opt for a generic or name-brand option. Your insurance may also help cover the cost of both Plan B or Ella, but a prescription from a health care provider is likely required. Hey Jane offers prescriptions for both brands to help lower the cost for you—click here to get started.

Does Plan B have a weight limit?

While emergency contraceptive pills do not have a weight restriction, Plan B is most effective for people weighing 165 pounds or less per FDA guidelines. Additionally, Ella works best in those weighing less than 195 pounds according to the FDA. An IUD is a good option for those with a higher weight or BMI who are looking to prevent pregnancy after unprotected sex and long term. If you’re not interested in an IUD but still want to prevent pregnancy, it’s absolutely safe to take an emergency contraceptive pill, no matter your weight.

Does Plan B cause infertility?

The science is clear: emergency contraception does not impact future fertility. Studies have shown that despite misconceptions, there are no long term side effects of using emergency contraception pills to prevent pregnancy. Emergency contraception does not increase the likelihood of miscarriage in the future, nor does it increase the risk for fetal abnormalities in future pregnancies. There is no evidence that emergency contraception permanently disrupts menstruation, either. 

What is the difference between Plan B and abortion pills (Plan C)?

Plan B is a specific brand of emergency contraception that’s available over-the-counter, but the name is often used to describe the entire category of medications  used to prevent pregnancy after sex. 

Plan C refers to abortion pills, used in medication abortions, that can be taken in person at a clinic or at home to safely and effectively end a pregnancy. 

Can you only by Plan B in an emergency?

Emergency contraception is safe, can be used any time you’ve had unprotected sex, and can be purchased in advance. There are no long-term side effects or impact on your fertility when you use emergency contraception so if you’re trying to prevent pregnancy, you can feel confident that it doesn’t have to feel like an “emergency” to take Plan B. 

Does Plan B expire?

What can make the experience feel like an emergency is locating the medication within the effective time frame, as not all pharmacies keep reliable stock of Plan B or Ella. To avoid the stress, you can get emergency contraception in advance and save it for a day when you need it! Plan B expires after 4 years and Ella expires after 3 years, meaning you can buy them in advance, tuck them away, and have them on hand for when you, a friend, or a loved one needs it.

Whether you're looking for birth control, emergency contraception, or abortion care, Hey Jane can help. Simply fill out our online intake form, connect with a judgment-free provider in 1 business day, and get care from the convenience of home.

Plan B or Plan C? Hey Jane can help with both
Image of a woman in front of the bathroom mirror and sink, holding two different orange prescription bottles. Image of a woman in front of the bathroom mirror and sink, holding two different orange prescription bottles.

Written by

Sally Borges, RN BSN

Sally Borges (she/her) is a registered nurse and writer with over a decade of experience serving abortion and reproductive healthcare patients. An ardent believer in shared clinical decision making, she gets a thrill when providing accurate, up-to-date education to anyone who’ll listen and seizes every opportunity to break sexual health stigma. Sally is a book lover, a creative lady with a penchant for music and visual arts, and, most importantly, a mother of four incredible people.

Published on:
February 9, 2024
Last updated:
June 12, 2026

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