The European manufacturer of an emergency contraceptive pill identical to its U.S. counterpart says the product does not work for women who weigh over 176 pounds. HRA Pharma says its drug begins to lose effectiveness at preventing pregnancy in women who weigh more than 165 pounds. The drug is identical the popular Plan B One-Step and other emergency contraceptives sold in the United States, where the average woman weighs 166 pounds — potentially too much to take the drug effectively. The European firm is adding a warning to its packaging. U.S. regulators are now evaluating whether to require similar labels.