Oral sex is good for women's health and makes you feel happier, according to a study which studied the effects of semen's 'mood-altering chemicals'.
The State University of New York study - which scientists carried out via survey rather than through practical experiment - compared the sex lives of 293 females to their mental health.
It follows research which shows that seminal fluid contains chemicals that elevate mood, increase affection, induce sleep and also contain at least three anti-depressants.
The researchers also claim that women who have regular unprotected sex are less depressed and perform better on cognitive tests.
Semen contains another of chemicals along with spermatozoa, including cortisol, which is known to increase affection, estrone, which elevates mood and oxytocin, which also elevates mood.
It also contains thyrotropin-releasing hormone (another antidepressant), melatonin (a sleep-inducing agent), and even serotonin (perhaps the best-known antidepressant neurotransmitter).
Given these ingredients - and this is just a small sample of the mind-altering 'drugs' found in human semen - Researchers Gallup and Burch, along with the psychologist Steven Platek, hypothesised that women having unprotected sex should be less depressed than suitable control participants.
Other recent findings from Gallup’s laboratory suggest that semen-exposed women perform better on concentration and cognitive tasks and that women’s bodies can detect 'foreign' semen that differs from their long-term or recurrent sexual partner’s signature semen.
They suggest the ability to detect foreign sources is an evolved system that often leads to unsuccessful pregnancies - via greater risk of preeclampsia - because it signals a disinvested male partner who is not as likely to provide for the offspring.
Their findings also suggest that women who have unprotected sex with their partners - and therefore are getting regularly inseminated by them - experience more significant depression on breaking up with these men than those who were not as regularly exposed to an ex’s semen, and that they also go on the rebound faster in seeking new sexual partners.