The label on a "morning-after" emergency contraceptive sold in Europe will be changed to alert consumers that it is not effective in women who weigh more than 176 pounds.
The new warning on the label of Norlevo will also caution that the pill starts to lose its effectiveness in women heavier than 165 pounds, and is not recommended for anyone over this weight, CBS News reported.
"When we became aware that there appeared to be an impact on efficacy (linked to weight), we felt it was our ethical duty as a drug manufacturer to report it and be transparent," Erin Gainer, CEO of HRA Pharma, the French manufacturer of Norlevo, told the New York Daily News.
Norlevo is identical in formula to the over-the-counter Plan B One-Step emergency contraceptive sold in the United States. The U.S. maker of Plan B One-Step, Teva Pharmaceutical Industries, declined to comment on the issue when asked about it by the Daily News and Mother Jones, CBS News reported.