Take Action pill: How this Plan B alternative prevents pregnancy

• The Take Action pill is a type of emergency contraception that is supposed to prevent pregnancy.
• If you take it within 72 hours of unprotected sex, you have a 75% to 89% chance of it working.
• After taking it, you may experience side effects like spotting, nausea, headache, and vomiting.

If you've had unprotected sex but don't want to get pregnant, you can take "the morning-after pill" to reduce your chance of pregnancy.

There are various brand names of morning-after pills, one of them being the Take Action pill, which is available over the counter. While the brand name Plan B is more commonly known, the Take Action pill has the same active ingredient and works the same way.

How does the Take Action pill work?

The primary way that the Take Action pill works to prevent pregnancy is by delaying or preventing ovulation, says Kate White, MD, MPH, an OB-GYN and Vice Chair of Academics, Department of OB-GYN, at Boston Medical Center.

Secondarily, the pill can prevent pregnancy by:

• Thickening your cervical mucus, which can help prevent an egg and sperm from joining.
• Thinning the uterine lining, which can prevent a fertilized egg from implanting in the uterus.

The sooner you can take the Take Action pill after unprotected sex, the better. If you take it within 72 hours of unprotected sex, you have a 75% to 89% chance of preventing pregnancy. The longer you wait, the less effective it will be.

However, the Take Action pill may not work, or be less effective if you weigh over 155 pounds or have a BMI of 26 or greater, says Sophia Yen, MD, MPH, reproductive health expert and the co-founder and CEO of women's telehealth provider Pandia Health.

A small 2016 study found that levels of levonorgestrel (the pill's active ingredient) were lower in the blood of participants with a higher BMI versus participants with a lower BMI.

If you weigh over 155 pounds or have a BMI of 26 or more, you have a better chance of preventing pregnancy if you take a prescription emergency contraception pill called Ella, which is effective for people between 155 and 195 pounds.

Take Action pill vs. Plan B

There is no medically significant difference between the Take Action pill and Plan B.

Both contain the same amount of the same active ingredient: 1.5 milligrams of levonorgestrel and both are 75% to 89% effective if taken within 72 hours. "Think of it like Advil and Motrin -- different brand names, but the same medication," says White.

How to use the Take Action pill

Using the Take Action pill is simple. All you have to do is take one pill by mouth as soon as possible after unprotected sex, says Yen.

However, if you vomit within two hours of taking the pill, it may not work, says White. In this case, contact your doctor to ask about taking another dose.

Additionally, if you have unprotected sex again after taking the Take Action pill, you will need another dose, since emergency contraception pills only cover you for that one previous incident of unprotected sex, and not future instances.

These are the only instances where you should take more than one pill.

Take Action side effects

After you take the Take Action pill, White says you may experience side effects for one or two days, such as:

• Vaginal spotting
• Nausea
• Vomiting
• Headache
• Dizziness
• Breast tenderness

Additionally, your upcoming period may be affected. Yen says the Take Action pill might make your period early or late. If your period is more than a week late, you should take a pregnancy test.

Risks of the Take Action pill

The Take Action pill is low-risk. "There have been no reports of serious problems out of the millions of women who have taken emergency contraception with this ingredient [levonorgestrel]," says White.

People who are allergic to levonorgestrel should not take this pill, says Yen. You would know this if you've ever had an allergic reaction to birth control that contains levonorgestrel. This includes birth control pills such as Alesse, Camrese, or Jolessa, and IUDs such as Kyleena.

Additionally, White says that some medications or supplements may interact with the Take Action pill, making it less effective, including:

• St. John's wort
• Some HIV medications
• Some anti-seizure medications

For a full list of medications, visit the Mayo Clinic's website.

Insider's takeaway

The Take Action pill is a type of emergency contraception that is very effective at preventing pregnancy if you take it within three days of unprotected sex, but the efficacy decreases the longer you wait to take it.

Although taking the pill multiple times isn't harmful to your health, the morning-after pill is meant for emergencies, not to be taken as regular birth control. If you find yourself taking it often, speak to your OB-GYN about more long-term contraception.

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