While this article doesn't necessarily present anything new, I thought I'd chime in with some related information. In males (at least), the hormone Testosteron

While this article doesn't necessarily present anything new, I thought I'd chime in with some related information. In males (at least), the hormone Testosterone is primarily responsible for sex drive (along with sufficiently low amounts of Estrogen). It's been studied quite extensively -- but webmd does a pretty good job of summarizing Testosterone's effect on libido in men: http://www.webmd.com/men/how-low-testosterone-can-affect-your-sex-drive http://www.webmd.com/men/how-low-testosterone-can-affect-you...