Oral contraceptives and Mr. Wrong

By Ann Griswold • Published: December 5th, 2008
Category: Health in a Heartbeat

Have you ever watched a couple walk down the street and wondered, ‘Why is she with him?’ A new study suggests birth control pills might interfere with a woman’s natural ability to sniff out Mr. Right by altering her sense of smell. The end result? She may end up walking down the aisle with Mr. Wrong.

A previous study found that women who are not on birth control respond favorably to men whose body odor reflects a different immune system composition than their own. Scientists say this natural attraction between men and women ensures they will produce children with stronger immune systems and fewer diseases. But birth control pills interfere with this process, encouraging women to respond more favorably to men whose scent reflects a similar immune composition to their own.

In a new study, researchers from the University of Liverpool in the United Kingdom uncovered slightly different results but came to a similar conclusion. The U-K researchers asked thirty-seven women to sniff T-shirts worn by various men. They found that women who were not on birth control had no preference when they sniffed the tee-shirts. But when the women started taking birth control pills, they were invariably attracted to less-than-ideal mates.

The researchers still aren’t sure how birth control pills alter women’s sense of smell, and more studies are needed to clarify their results.

And like anything, the key to compatibility likely involves a lot more than just basic biology.