If you thought the “morning-after” pill was a reliable way to ward off an unwanted pregnancy, think again – especially if you weigh more than 75kg.
Reuters reports that the US Food and Drug Administration (FDA) is looking into whether emergency contraceptive pills fail to work for women over a certain weight, after scientists in France said a brand of pills sold there was ineffective for overweight women.
The commonly sold emergency pills in India too contain the same synthetic hormone as used in this particular pill in France – levonorgestrel, a synthetic version of a hormone called progestogen.
Scientists at French drugmaker HRA Pharma discovered that its emergency contraceptive under the brand name Norlevo began losing effectiveness in women who weigh about 165 pounds (75kg), and was not effective at all in women weighing over 176 pounds (80kg), according to reports on CNN and elsewhere.
After European health regulators ordered a label change for Norlevo, requiring it to include the drug’s diminishing effectiveness based on weight, the FDA has begun reviewing the effects of weight on the efficacy of pills sold in the US.
The FDA will then decide whether to add a warning to the drug’s label.
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,” said FDA spokeswoman Erica Jefferson on Monday via email, reports Reuters.
“The agency will then determine what, if any, labeling changes to approved emergency contraceptives are warranted.”
HRA was conducting research on another topic related to Norlevo when scientists realised there was “a clear impact of weight” on the drug’s effectiveness, said HRA chief executive Erin Gainer, according to CNN.
The Norlevo label is expected to be changed early in 2014, reports said.
Norlevo is similar to morning-after contraceptives sold in the US under the brand name Plan B One-Step and in generic versions under other names.
Emergency contraceptives pills are taken by women following unprotected sex to avoid pregnancy. The pill is to be popped within 72 hours of sexual intercourse to be effective.
In India, just like in the US, the “morning-after” pills are sold over the counter – meaning that they do not require a doctor’s prescription.