Semen acts as an anti-depressant Semen makes you happy. ... The researchers think this is because mood-altering hormones in semen are absorbed through the vagina. In fact, the results aren't a complete surprise because semen does contain several mood-altering hormones, including testosterone, oestrogen, follicle-stimulating hormone, luteinising hormone, prolactin and several different prostaglandins. Some of these have been detected in a women's blood within hours of exposure to semen. The question many people will ask is whether oral sex could have the same mood-enhancing effects. "Since the steroids in birth control pills survive the digestion process, I would assume that the same holds true for at least some of the chemicals in semen," Gallup says. "Come on, get happy" takes on a whole new meaning for us girls.