The most obvious effect of birth control pills is, well...birth control. But the pill may have subtler effects, too. Like influencing which guy a woman goes for, and her satisfaction with him—in bed and out. So says a study in the journal Proceedings of the Royal Society B.

Researchers quizzed 2,500 mothers on their relationship satisfaction. And they found that women who met Mr. Right while on the pill were happier with their partner’s “daddy credentials”—finances, intelligence and so on. But the same women were less satisfied in the sack than non-pill-takers, rating their mates as less sexually adventurous or attractive.

So why the sizzle fizzle? Previous studies suggest women are attracted to men genetically different from themselves—which ups the odds of a healthy kid—but on birth control, the opposite seems true. So the authors say the pill might interfere with a woman's innate sense of sexual chemistry.

But the pill has its perks. Women stayed together longer with partners they met while on the pill, and were less likely to want a separation. Either way, this study suggests the pill is more than just birth control. It could be boyfriend control, too.

—Christopher Intagliata

[The above text is a transcript of this podcast.]