Plan B May Lose Its Effectiveness For Women Over 176 Pounds


Plan B, the popular brand of emergency contraception that is now available to all U.S. women over the counter, may not work as well for heavier women. As Mother Jones reports, a European company that manufactures an identical morning after pill has added a warning label to its product noting that it begins losing its effectiveness for women over 165 pounds, and may be totally ineffective for women over 176 pounds.

The European drug, Norlevo, uses a compound called levonorgestrel to prevent pregnancy up to 48 hours after sexual intercourse. That’s the same ingredient in Plan B One-Step, which is currently the only morning after pill that can be purchased by women of all ages without a prescription. Norlevo’s packaging is being updated to reflect the potential weight limits, but it’s unclear whether the company that manufactures Plan B One-Step will make a similar update to its own warning labels.

HRA Pharma, the company that makes Norlevo, decided to update the drug’s packaging after a 2011 study suggested that levonorgestrel-based emergency contraception is less effective for women with a higher Body Mass Index (BMI). HRA Pharma reviewed the clinical data and requested permission to make the change from European pharmaceutical regulators. The request was approved earlier this month.

If the research in this area is accurate, the weight limits could have a big effect on women in this country. The average U.S. woman weighs 166 pounds, according to the Centers for Disease Control.

The 2011 study on this subject recommended that heavier women should ideally be offered a copper IUD, which is even more effective at preventing pregnancy than the morning after pill. Getting an IUD is also a more involved process than taking a pill, however, since it requires scheduling an appointment to get it inserted. It also used to be significantly more expensive, running up hundreds of dollars in co-pays — but thanks to Obamacare’s new birth control benefit, IUDs are now covered free of charge. Despite the fact that the copper IUD is an extremely effective option, the majority of U.S. doctors don’t tell their patients it can be used for emergency contraception.

The fight to expand U.S. women’s access to emergency contraception has stretched on for years, and the Food and Drug Administration (FDA) only officially moved it out from behind the counter this June. The FDA has maintained an exclusive deal with Teva Pharmaceuticals, the company that manufactures Plan B One-Step — so generic versions of the pill, as well as two-step versions with slightly different drug compositions, aren’t yet available over the counter for younger girls. And unless Teva decides to update its packaging to reflect the potential weight limits, the generic versions of Plan B One-Step won’t be able to change their warning labels, either.