From a new article in the Proceedings of the Royal Society: Biological Sciences, researchers found that women taking birth control pills preferred men with a "genetically similar scent." (MSNBC)
The researchers suggest that, because birth control hormones mimic pregnancy, that the brains of women who take them are put into a non-mate-seeking state and so don't choose men who smell "different."
I don't really know what this all means, but it's another reason in the litany of reasons not to take birth control hormones.
Let's review the side effects:
Loss of libido
And now impaired mate selection?