Morning After Pill Less Effective On Plus-Sized Women
November 26, 2013

Morning After Pill Less Effective On Plus-Sized Women

Brett Smith for - Your Universe Online

A certain emergency contraception made in Europe is now being packaged to show that it is less effective for women weighing over 176 pounds, according to the pill’s maker HRA Pharma.

The company said it became aware there was "a clear impact of weight" on the effectiveness of its contraceptive pill Norlevo while conducting research on another related issue.

HRA Pharma chief executive Erin Gainer told CNN's Jacque Wilson that company scientists saw Norlevo losing its effectiveness when women reached 165 pounds and showed an "absence of effectiveness" at about 176 pounds.

"We felt it was our ethical duty ... to report those results to our health authorities here in Europe," Gainer said.

Norlevo is indistinguishable from the emergency contraceptive Plan B One-Step available in the US, said Kelly Cleland, a public health expert at Princeton University. Both pills include the active ingredient levonorgestrel, a synthetic version of the hormone progestogen. Emergency contraceptives work by disrupting ovulation, essentially preventing the fertilization of an egg.

Food and Drug Administration (FDA) spokeswoman Erica Jefferson told CNN that it "is currently reviewing the available and related scientific information on this issue, including the publication upon which the Norlevo labeling change was based.

"The agency will then determine what, if any, labeling changes to emergency contraceptives are warranted,” she added.

The American version of the pill is currently available without a prescription to anyone of any age. Generic versions of the drug are marketed as Next Choice One Dose and My Way.

"Actavis' Next Choice One Dose is approved by the FDA as a safe, effective and therapeutically equivalent treatment option to its brand counterpart," Actavis spokesman David Belian told CNN. "Therefore, should any update to the Plan B labeling take place, we would make the appropriate change to our product as well."

Anna Glasier, an expert in reproductive medicine at the University of Edinburgh who published a study on emergency contraception in 2011, said it is unclear why emergency contraceptives may be less effective for overweight women. The 2011 study revealed obese women had three times the risk of getting pregnant after taking emergency contraception compared to those with a normal body weight.

"There has been some evidence over the years that low doses of progestogen-only contraceptives have less efficacy in heavier women, but we do not know why," Glasier told CNN. She added, "it is well recognized that body weight affects the way drugs are metabolized."

Glasier also noted the number of obese women in her study was not representative, making it difficult to make generalizations about the effect of body weight.

"You are probably better to take (levonorgestrel) after unprotected sex than just to leave it to chance even if you are obese," Glasier said. "Because Plan-B One Step is now available over-the-counter and is by far the easiest EC method to get, this is the method that most women are familiar with."

According to the Centers for Disease Control and Prevention (CDC), "The best way to reduce the risk of unintended pregnancy among women who are sexually active is to use effective birth control correctly and consistently.”