Multiple studies have shown the impact of user weight on the effectiveness of the emergency contraceptive drug Plan B One-Step. New packaging for the EU version of this drug includes warnings that it is not recommended for women weighing over 165lbs.

But here in US the FDA has remained silent, despite the fact that the average American woman weighs 164lbs and that emergency contraception was used here almost 6 million times between 2006-2010 alone.