Semen is good for your mental and physical health, a study has found.

Whether it enters the body orally or via unprotected sex, the “mood altering chemicals” contained within seminal fluid reduce depression, increase affection and help you sleep.

The State University of New York study found that women who regularly have unprotected sex are less depressed.

Medical Daily points out semen contains mood-elevating estrone and oxytocin, cortisol, melatonin, anti-depressant prolactin, thyrotropin releasing hormone and serotonin.

The study surveyed the sex lives and mental health of 293 women from the SUNY-Albany campus.

Researchers also asked respondents to complete the Beck Depression Inventory, which is commonly used to measure mood disorders.

The results revealed that sexually active women who “never” used condoms showed significantly fewer depressive symptoms than those who “always” or “usually” used condoms.

The findings, which were published in the Archives of Sexual Behaviour journal, also found women who described themselves as “promiscuous” yet used condoms were as depressed as women who practice abstinence

The team says this suggests it is semen, not just sex, that makes women happy.

It comes in the same month Gordon Gallup, a psychologist at SUNY-Albany, proposed semen also helps women suffering from morning sickness.

Gallup theorised that pregnant women often feel nauseous because their bodies are rejecting the semen’s genetic material as alien.

It thus follows that ingesting the same sperm would allow the body to build up a tolerance, The New York Daily News reported.