Plan B One Step, Next Choice One Dose and other over-the-counter drugs that are supposed to prevent pregnancy up to 72 hours after having unprotected sex have just one slight flaw. If you happen to weigh over 165 pounds the drug becomes far less effective. If you weigh more than 176 pounds the drug is completely ineffective.
Data for the years 2007 to 2010 show the average weight of American women 20 years and older is 166.2 pounds—above the weight at which emergency contraceptive pills that use levonorgestrel begin to lose their effectiveness. The average weight of non-Hispanic black women aged 20 to 39 is 186 pounds, well above the weight at which these pills are completely ineffective. A CDC survey published in February found that 5.8 million American women used emergency contraceptive pills from 2006 to 2010.
New leaflets warning women about the weight limits will appear in every box of Norlevo sold in Europe in the first half of 2014. The new packaging slip will read, in part: “Studies suggest that Norlevo is less effective in women weighing [165 pounds] or more and not effective in women weighing [176 pounds] or more” and that Norlevo “is not recommended…if you weigh [165 pounds] or more.”
Moral of the story? If you plan on having random, unprotected sex you better be skinny as fuck if you plan on relying on the morning after pill to avoid that little bundle of joy nine months after that one-night stand with the cute guy at the bar who bought you an apple martini and stiffed the bartender on a tip.