The “psych” in semen

My post on mind control properties in semen still attracts a disturbing amount of attention. So to appease your curiosity — and, I’ll admit it, mine — I’ve decided to do a little more investigation into the compounds in semen that may enter the bloodstream after sex. Some may have an indirect effect on the recipient’s hormones. A few may breach the blood-brain barrier, directly influencing mood and sex drive. Several, but not all, of the chemicals have been studied and proven to pass through the vaginal walls. From an evolutionary perspective, mood-modulating components in semen may give a woman an incentive to be in a committed relationship with regular, frequent sex. Apparently, the goo is bonding.

The information below comes from SUNY Albany evolutionary psychologists Gordon Gallup and Rebecca Burch, whose fascinating study on semen and depression I describe in BLONDES. Gallup and Burch wrote a chapter, “The psychobiology of human semen,” published in a compilation of research on sexuality. What they describe, I think, is fascinating.

The primary putative mind-altering ingredients in semen:

Luteinizing hormone: astounding concentration in semen; linked to high sperm count and motility. Absorption into female bloodstream may facilitate or even induce ovulation.

Prolactin: influences maternal behavior, oxytocin secretion; mediates bonding

Estrone and estradiol: assists in recipient’s absorption of other compounds such as progesterone; may boost woman’s sexual motivation and mood

Testosterone: may increase sex drive and motivation; the more intercourse, the higher the testosterone levels in women, and the stronger the sexual desire. More than half the amount of testosterone in sperm has been found to be absorbed by the vagina.

Cytokines: these are the “warriors,” they suppress immune reaction to semen invading the vagina and cervix and therefore increase likelihood of pregnancy

Enkephalins: these opioids may contribute to orgasmic experience. They may decrease anxiety and cause drowsiness after sex.  There’s also speculation that they assist in immune function and “reinforcing effects” — making a woman come back for more, i.e. addiction  (although the absorption rate in female bloodstream is unknown)

Oxytocin: assists in stimulation of ovulation, increases production of other hormones, initiates bonding, facilitates orgasmic contractions; may strengthen bonding and make sexual activity more rewarding

Placental proteins, including human chorionic gonadotrophin (hcg) and human placental lactogen: associated with sperm motility; may increase chances of pregnancy

Relaxin: made in the prostate, this hormone may facilitate fertilization, implantation, and uterine growth. The role of relaxin suggests that women should keep having a lot of sex during pregnancy because sperm has pregnancy-maintaining properties. Relaxin also facilitates implantation and prevents preterm labor.

Thyrotropin-releasing hormones: potential anti-depressive; works by stimulating the release of thyroid-stimulating hormone, which in turn triggers hormone production in the mood-mediating thyroid gland. In pill form, it’s used to treat PMS and depression.

Serotonin: increases sperm motility.  It also mediates mood, although not much known yet about vaginal absorption. Even if it doesn’t make it to the brain, it may indirectly alter behavior and emotions by contributing the building blocks of serotonin

Melatonin: increases effects of steroid hormones; induces sleepiness and fatigue, which may help the woman relax after sex; may stimulate reproductive function, also mood mediator; low melatonin levels are associated with depression and “reality disturbance”

Tyrosine: a precursor of neurotransmitters such as dopamine, the hormone of reward and addiction, and norepinephrine, involved in attention and arousal

Oh, and there’s also sperm in there, the DNA-bearing courier. Sperm is less than 3 percent the total volume of semen. But as it turns out, the bath water is nearly as important as the baby.

n.b. Although not yet studied, researchers suspect that these chemicals in semen may also enter the bloodstream through mucous membranes when having oral and anal sex. If so, straight women aren’t the only lucky recipients.