Plan B and Plan B One Step are emergency contraceptives intended to reduce the possibility of pregnancy following unprotected sexual intercourse or a known or suspected contraceptive failure, such as a condom breakage.

FDA communication on levonorgestrel emergency contraceptive effectiveness and weight

The FDA has completed a review of available scientific data concerning the effectiveness of levonorgestrel (LNG) emergency contraceptives (ECs) in women who weigh more than 165 pounds or have a body mass index (BMI) above 25 kg/m². The data are conflicting and too limited to reach a definitive conclusion as to whether effectiveness is reduced in this group. The FDA does not believe that a change in the labeling for LNG EC products is warranted at this time. There are no safety concerns that preclude use of LNG ECs in women generally, and the FDA continues to believe that all women, regardless of how much they weigh, can use these products to prevent unintended pregnancy following unprotected sexual intercourse or contraceptive failure. The most important factor affecting how well emergency contraception works is how quickly it is taken after unprotected sex.

Given that the currently available data are inconclusive, the FDA believes further research by the manufacturers of these products on the possible impact of weight or BMI on effectiveness should be a priority.

The FDA will continue to monitor and review information on these products as it becomes available and will communicate to the public as needed. Consumers and health care professionals are encouraged to report adverse reactions from the use of LNG ECs to the FDA’s MedWatch Adverse Event Reporting program at www.fda.gov/MedWatch or by calling 1-800-FDA-1088.

For additional information and background please see:

Plan B: Health care professional Questions and Answers
Plan B: Consumer Questions and Answers

Labeling and Regulatory History from Drugs@FDA

• Levonorgestrel (marketed as Plan B and Plan B One-Step) prescribing and labeling information