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Claim that Plan B emergency contraceptive pill has a weight limit needs context

Data detailing the effectiveness of Plan B in people who are considered overweight is “conflicting and too limited to make a definitive conclusion,” the FDA says.
Credit: Artinun - stock.adobe.com
Emergency contraceptive pills in blister pack on blurred background

On May 2, a draft opinion suggesting the Supreme Court may overturn Roe v. Wade, which federally protects the right to abortion in the United States, was leaked to POLITICO. The next day, the Supreme Court confirmed the authenticity of the draft opinion, and Chief Justice John G. Roberts Jr. ordered an investigation into the leak. The court said the draft does not represent a final decision.

The leak sparked conversations on social media about reproductive rights and access to emergency contraceptives like the Plan B One-Step pill. But a recent tweet claims Plan B has a weight limit of 155 pounds, and Google Trends data shows people are searching whether Plan B works for people who are overweight.


Does the Plan B One-Step emergency contraceptive pill have a weight limit? 



This needs context.

This claim needs context. While health experts say weight can influence the effectiveness of levonorgestrel emergency contraceptive pills, like Plan B One-Step, the FDA says the scientific data “are conflicting and too limited to make a definitive conclusion.” 


Emergency contraception is not a regular method of birth control, according to the Centers for Disease Control and Prevention (CDC). It is typically used after people have sex without birth control, or if the birth control method failed; for example, if a condom broke. 

Forms of emergency contraception available in the United States include the copper intrauterine device (IUD) and emergency contraceptive pills (ECP), such as levonorgestrel, which is known as the morning-after pill. ECP can be taken up to five days after unprotected sex, “but the sooner the pills are taken, the better they will work,” the CDC says on its website.

Plan B One-Step is a levonorgestrel tablet that is taken in a single 1.5 milligram dose. It works by preventing the release of an egg from the ovary or preventing fertilization of the egg by sperm, according to the National Library of Medicine. It can also change the lining of the uterus, preventing a fertilized egg from attaching.

According to the American College of Obstetricians and Gynecologists (ACOG) and Planned Parenthood, body weight may influence the effectiveness of levonorgestrel, including Plan B One-Step. 

“Levonorgestrel emergency contraception may be less effective in women who are overweight with a body mass index (BMI) of 25 to 29.9 or obese with a BMI of 30 or greater,” ACOG told VERIFY in a statement. “However, oral emergency contraception should not be withheld from women who are overweight or obese because no research to date has been powered adequately to evaluate a threshold weight at which it would be ineffective.” 

According to the Food and Drug Administration (FDA), the effectiveness of levonorgestrel emergency contraceptives like Plan B One-Step first came into question after the French manufacturer of Norlevo, which is an emergency contraceptive containing levonorgestrel marketed in Europe, submitted data to European regulators stating its product did not work for people who weigh more than 176 pounds. 

Regulators in France and other European countries agreed to label changes proposed by the manufacturer, stating that Norlevo is less effective in people weighing 165 pounds or more and not effective in people who weigh over 176 pounds in November 2013, the FDA says on its website

After the action was taken in France, the European Medicines Agency (EMA) conducted a full review of the available data and determined that the data “were too limited and not robust enough to conclude with certainty that contraceptive effectiveness is reduced with increased body weight,” according to the FDA. 

The FDA completed its own independent review of available scientific data concerning the effectiveness of levonorgestrel emergency contraceptives in people who weigh more than 165 pounds or have a BMI of more than 25, which is classified as overweight for U.S. adults aged 20 years old and older, and also determined that the data are conflicting and too limited to make a definitive conclusion. 

“There are no safety concerns that preclude the use of levonorgestrel emergency contraceptives in women generally, and the FDA continues to believe all women, regardless of how much they weigh, can use these products to prevent unintended pregnancy following unprotected sexual intercourse or contraceptive failure,” the FDA says. 

A spokesperson for Foundation Consumer Healthcare (FCH), the maker of Plan B One-Step, told VERIFY in a statement that it agrees with the FDA’s assessment. 

“There have been no prospective, controlled studies that have assessed the efficacy of levonorgestrel 1.5mg related to body weight or BMI,” the spokesperson said. “We hold the same belief as the FDA, which states that there are no safety concerns that preclude the use of levonorgestrel emergency contraceptives in women generally, and continue to believe that all women, regardless of how much they weigh, can use these products to prevent unintended pregnancy following unprotected sex or contraceptive failure.” 

The FDA and Plan B One-Step both say the most important factor affecting how well emergency contraception works is how quickly it is taken. 

“When emergency contraception is taken as directed, within 72 hours after unprotected sex or birth control failure, it can significantly decrease the chance that a woman will get pregnant. In fact, the earlier the product is taken after unprotected intercourse, the better it works,” the spokesperson said. 

Plan B One-Step also says it does not recommend that women over 155 pounds take two doses of its ECP to try to prevent pregnancy, as alleged in another online claim

“Plan B One-Step is approved by the FDA as a 1.5mg levonorgestrel tablet that helps prevent pregnancy before it starts when taken within 72 hours after unprotected sex or birth control failure,” the spokesperson said. “Plan B should always be used as directed in accordance with the product’s label.” 

Outside of the copper IUD, which the ACOG says is not affected by body weight, the only FDA-approved emergency contraceptive in the U.S. that does not contain levonorgestrel is ella, or ulipristal acetate. However, the ACOG says some research suggests that ulipristal acetate has lower effectiveness among obese people. 

More from VERIFY: Yes, states can pass their own abortion laws if Roe v. Wade is overturned

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