Alright, nobody (except porn stars) gets totally excited about semen - but it turns out that this man-made substance might actually have more benefits than we thought. Consider, for example, the findings of a 2002 study that found that semen might have anti-depressant properties for the recipient.

Psychologists at the State University of New York at Albany published a study in the Archives of Sexual Behavior looking at the potential role of semen in lifting the mood of women. They studied sexually active females and found that those who usually engaged in sex without a condom reported being happier than those who abstained or always used protection. Critics claimed that women willing to engage in unprotected sex - those who are, for example, coupled or willing to take risks - might have sunnier dispositions to begin with, but the researchers insisted that every step had been taken to ensure control - and that it was indeed the semen that was causing the mood boost.

Those findings are still controversial, but semen does have other important properties. "Seminal plasma evolved to control and manipulate the female reproductive system so as to work toward the best interests of the donor - the male," explained Gordon Gallup, Jr., an evolutionary psychologist at SUNY Albany and lead author of the study, to a columnist at Popular Science. " If you begin to think about semen in those terms, then the fact that semen might have antidepressant properties becomes a lot more interesting in that it may promote bonding between the female and her sexual partner." And science .backs it up - semen contains estrogen, prostaglandins and oxytocin, three compounds that are known to lower depression levels and increase intimacy