November 25, 2013

A Weighty Question: Does “Plan B” have a Weight Limit?

iStockphoto/Thinkstock Mother Jones today has a great piece out on how a version of “Plan B” manufactured in Europe is less effective for women who weigh more than 165 pounds, and rendered completely ineffective for women whose weight tops 176 pounds.

By Dina Fine Maron

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This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American

: iStockphoto/Thinkstock

Mother Jones today has a great piece out on how a version of "Plan B" manufactured in Europe is less effective for women who weigh more than 165 pounds, and rendered completely ineffective for women whose weight tops 176 pounds. (The average adult American woman weighs in at 166.2 pounds, notes CDC.) Though the European drug, Norlevo, is not licensed under that brand name for use here in the United States, I’ll be keeping my eyes out to see what happens to emergency contraception in the United States, which includes similar levels of synthetic hormones.

When the U.S.-version of Plan B was originally approved in 1999, it did not include any assessment specific to a woman’s weight. I reached out to FDA for further guidance on the future of emergency contraception in the United States. In an email, the agency states: “The FDA is currently reviewing the available and related scientific information on this issue, including the publication upon which the Norlevo labeling change was based. The agency will then determine what, if any, labeling changes to approved emergency contraceptives are warranted.”

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