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Plan B: What You Need To Know

Updated: Aug 16, 2019

By Jill

When I first took Plan B, I was an 18 year old college freshman. I hadn’t had ANY sex education in high school, and I felt unprepared and scared to take a pill I knew nothing about. I knew I didn’t want to be pregnant, but I didn’t know how the pill worked or how it would affect me. Looking back, I made the right decision for myself and my body. But how could I have known what the right choice was without knowing basic facts about the over-the-counter pill Plan B?

So... What is Plan B?

Plan B is an emergency contraception (EC) used to prevent pregnancy for people engaging in penetrative sex (with a penis and vagina). It comes in pill form that you ingest orally. You may choose to take Plan B for a variety of reasons: the condom broke, your partner didn't pull out early enough or maybe you don't remember if you used one, among many more.

You may see different brands of EC as you're strolling down the aisle, but they all work the same — "name brand" is no better than generic. The active ingredient in Plan B and other over-the-counter EC pills is Levonorgestrel. Levonorgestrel is also an active ingredient in many different types of birth control (BC).

However, Plan B contains 1.5mg of Levonorgestrel — more than 100 times the amount found in BC. While this may sound intense, and maybe even dangerous, it’s not! Most of the side effects of birth control are caused by the much smaller, continuous levels of these hormones. In contrast, Plan B will overload your body with Levonorgestrel, but it will leave your system in a few days. This means the side effects of EC are short term and will disappear once your body stabilizes again.

The side effects of EC are often short term, disappearing once your body stabilizes again.

Taking Plan B multiple times does not decrease its effectiveness or pose an increased risk of infertility. Depending on a person’s BMI, two Plan B pills may even be the correct dosage for best results (please check with a doctor before you attempt to do a double dosage).

If your BMI affects the effectiveness of an OTC emergency contraceptive, a copper IUD or the ella morning after pill may be more effective. The ella is an emergency contraceptive pill that can be taken within five days after sex, reduces your risk of pregnancy by 85 percent, but you need a doctor's prescription to obtain it.

Other forms of contraception have lower risks of pregnancy, and taking Plan B often may disturb your menstrual cycle. While this can be annoying, it does not pose any health risks.

However… There are still some pretty unpleasant side effects!

  • Often people experience:

  • Nausea

  • Abdominal pain

  • Fatigue

  • Heavier (or lighter) menstrual bleeding

  • Breast tenderness

  • Vomiting

  • Diarrhea

Some people who take Plan B experience multiple side effects, while others experience none. One person may even experience different side effects each time they take Plan B. Since your body is always changing, reactions over time can vary. However, the recommended dosage and administration instructions do not change. Understanding the recommended instructions can significantly reduce the chances that you will become pregnant.

What does “within 72 hours” really mean?

Recently a friend of mine told me she waited two days to decide whether or not to take Plan B, since she had a 72 hour window to think about it. While there are many valid and real barriers to accessing emergency contraception, if you are able to access Plan B quickly, DO IT QUICKLY.

Plan B should be taken within 72 hours of sex, but what many people don’t know is that Plan B, and other generic pill emergency contraception, becomes significantly less effective over time. If taken within 24 hours, Plan B is 95 percent effective. However, if taken within 72 hours, Plan B is 89 percent effective.

Plan B should not be taken as a primary form of contraception, as other methods are much more likely to prevent pregnancy. It's an emergency contraceptive — so let's keep it that way, folks!


WANT a bit of the dirty deets?

Read three women's experiences taking Plan B and the aftermath.


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