The Morning After: Emergency Contraception with Plan B

The Plan B pill is America’s most widely used over-the-counter (meaning no prescription necessary) emergency contraception.

How effective are morning-after pills like Plan B?

Levonorgestrel morning-after pills like Plan B One-Step, My Way, My Choice, and Option 2 are about 87% effective at preventing pregnancy if taken within three days of having unprotected sex.  Although studies suggest levonorgestrel continues to remain at least partially effective up to five days after unprotected sex, it’s best to take this form of emergency contraception as soon as possible within the first 72 hours.

Timing is everything when taking a morning-after pill like Plan B, but body weight also impacts levonorgestrel’s efficacy.  Studies suggest the medication does not work as well in women with body mass indexes (BMI) greater than 30.  If that’s the case for you, Ella, another morning-after pill is a better option.

As mentioned above, there are many different brands of levonorgestrel morning-after pills: Plan B One-Step, Option 2, My Choice, and AfterPill are just a few examples on the market.  It’s important to know that they all work the same way, have the same active medicine—levonorgestrel—and effectiveness. The only difference you’ll find between them is the price.

How do I use a morning-after pill like Plan B?

Take the levonorgestrel morning-after pill as soon as possible after unprotected sex - ideally, within the first three days.  If you vomit within three hours of taking the pill, it’s best to take another one to ensure your body absorbs enough of the medication.

If you do not get your period within three weeks of taking the pill, take a pregnancy test.  Medications like Plan B do not harm or disrupt pregnancy once fertilization has occurred. It also does not negatively impact your ability to get pregnant in the future.

Is Plan B safe?

Any person assigned female at birth, of any age, who has had unprotected sex, does not want to become pregnant and is considering taking a levonorgestrel morning-after pill like Plan B should take it.  The medication is safe for almost everyone, except those with an allergy to levonorgestrel.

If side effects occur, they usually don’t last long and improve on their own. Some women get an upset stomach and feel nauseous or lightheaded. You may develop some breast tenderness after taking the morning after pill or feel fatigued. Your next period may be different - it might come earlier or later or be heavier or lighter. On the other hand, many women don’t experience any side effects at all.

It’s important to remember that although the morning after pill is effective at preventing unintended pregnancy, it does not disrupt a pregnancy once fertilization occurs and cannot prevent sexually transmitted infection (STI) that might result from unprotected sex.

Do any of my medications interfere with morning-after pills like Plan B?

Certain medications can affect how the body metabolizes levonorgestrel, making it less effective at preventing pregnancy. These medications include:

• The flowering plant St John’s Wart
• Certain antiviral medications used to treat conditions like COVID-19 and HIV
• The antibiotic Rifampin and the antifungal Griseofulvin
• Certain anti-seizure, psychiatric, and migraine prophylaxis medications like carbamazepine,  phenytoin, and topiramate.

You can ask Mona about any medications you’re taking to determine if a morning-after pill like Plan B is right for you.

How much do Plan B and other levonorgestrel morning-after pills cost?

Plan B is the most well-known over-the-counter morning-after pill. It is also one of the most expensive on the market; it usually costs $40-$50 and can be found on the shelves at most retail pharmacies and larger grocery stores.  Other levonorgestrel morning-after pills cost much less and are just as effective; they can cost between $10 and $30 plus shipping if purchased from a website like Mona.

If you have health insurance or Medicaid, you may be able to get Plan B for free, but you’ll most likely need a prescription for a health care provider for insurance to cover it.

With Plan B, timing is crucial. It’s a good idea to purchase several doses to keep on hand before you need them. Plus, it prevents the anxiety and stress of racing the clock. After all, a trip to your medicine cabinet is shorter than a trip to the pharmacy.