7 massive misconceptions about Plan B (the morning after pill)

By Sara Kloepfer

Emergency contraception may seem self-explanatory — when your plan A fails (or isn’t even an option), it is, quite literally, time for Plan B. The morning after pill, sold under the brand name Plan B among others, prevents pregnancy after unprotected sex. But there are a lot of myths and misinformation surrounding Plan B out there, from how it works to potential side effects. We’re here to set the record straight about these common misconceptions:

Myth #1: Plan B is an abortion pill

Not at all. Plan B contains a completely different ingredient than the abortion pill, which is, in fact, two medicines, mifepristone and misoprostol. Plan B contains levonorgestrel, the same active ingredient as regular birth control pills, just at a higher dose. Plan B does not terminate a pregnancy, but rather prevents it by delaying ovulation. So if you are already pregnant or think you might be, Plan B will not affect the existing pregnancy. 

Myth #2: You have to take Plan B within 24 hours for it to work

Ironically, the morning after pill does not literally need to be taken the morning after unprotected sex in order for it to work. Plan B can prevent pregnancy if taken up to 72 hours after unprotected sex. However, the sooner you take it, the more effective it is, which is why it is recommended that you take Plan B within 12 hours of unprotected sex. If taken within 24 hours of unprotected sex, Plan B is 95% effective, and if taken between 48 and 72 hours afterwards, the efficacy rate drops to 61 percent. 

Myth #3: Plan B works for everybody

Although this isn’t widely advertised, multiple research studies suggest that Plan B is less effective for people with a higher BMI. If you weigh more than 165 pounds or have a BMI over 25, ella (an alternative morning after pill) or the copper IUD are better options. ella prevents pregnancy up to 5 days after unprotected sex, and unlike Plan B, does not get less effective as time passes, but you need a prescription to get it. If you are on hormonal birth control (the pill, ring, patch, or shot), ella is not the best emergency contraception option because it makes both medications less effective. 

Plan B is also not recommended if you are allergic to levonorgestrel or any other ingredients in the pill, or if you have abnormal vaginal bleeding. Some medications and herbal remedies can interact with Plan B and make it less effective, so talk to your healthcare provider if you are taking anything else. 

Myth #4: It’s a pain to buy Plan B 

Actually, Plan B is available on the shelf at pharmacies, and purchase does not require a prescription or ID. There is also no age or gender requirement to purchase it. Prices vary by brand, but if you are stocking up ahead of time (which we highly recommend!), it’s usually cheapest to order online — don’t worry, every brand of morning after pill is equally effective. Some health insurance plans cover Plan B, but you may need a prescription in order for insurance to pay for it.

Myth #5: Plan B has awful side effects 

Severe reactions to Plan B are pretty rare. Most side effects usually pass within 24 hours. The most common side effects include nausea, abdominal pain, fatigue, headache, dizziness, breast tenderness, vomiting, diarrhea, and irregular menstrual bleeding. If you vomit within 2 hours of taking Plan B, you may not have absorbed the medication and might need to take another dose. 

Less common reactions include migraine or severe headache, lower abdominal pain, painful menstruation, and vaginal discharge. Contact a healthcare professional if symptoms continue for more than 48 hours, or if you experience any of the following side effects: itching and rash, cramping or severe pain in your stomach or belly prior to your next normal period, uterine hemorrhage, or vaginal hemorrhage.

Myth #6: If you took Plan B in the morning, you don’t need to use protection that night 

Plan B does not protect against future sexual encounters, so resume your regular birth control method after taking Plan B. If you’ve taken plan B because of missed birth control pills, ask your pharmacist or healthcare provider about the best way to resume taking them. Remember to use another method of contraception, such as condoms, until your birth control is fully reliable again.

Myth #7: You’ll become infertile if you take Plan B too much 

Taking Plan B absolutely won’t hurt your chances of getting pregnant later on. Actually, if used on more than one occasion, the cumulative pregnancy rate will be higher. Translation: the more frequently you take Plan B, the less effective it is overall. Also, if Plan B is taken more than once within a menstrual cycle or more than the occasional once-a-month use, it may impact your period, including a shorter or longer cycle and a heavier or lighter period.


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