Published online Oct 22, 2018. doi: 10.5317/wjog.v7.i2.17
Peer-review started: June 22, 2018
First decision: September 3, 2018
Revised: September 10, 2018
Accepted: October 12, 2018
Article in press: October 12, 2018
Published online: October 22, 2018
Endorphins are the body’s natural opioids that are created and released by the central nervous system, hypothalamus and pituitary gland. Endorphins have a reputation for pain reduction, enhancing excitement or satisfaction, boosting confidence, enabling control of emotions and generating feelings of euphoria, and are involved in the natural reward cycle. There is also evidence in the literature suggesting the role of endorphins in sexuality (including sexual function and sexual behaviours), as they may regulate the release of sex hormones, prolactin and growth hormone, which are involved in sexual function and love. Endogenous oxytocin is another intrinsic hormone whose role in inducing labour contractions, the delivery of the baby and stimulating lactation has been well studied. However, the potential impact of endorphins and oxytocin on sexuality and romantic relationships is not well understood. This article reviews the research on endorphins and endogenous oxytocin and how they relate to human sexuality and romantic relationships. Some animal studies report the effect of endorphin and oxytocin on sex hormones and mating behaviours, but these findings have not been supported by research into human behaviour, indicating many gaps in knowledge relating to the association between these hormones and human sexuality.
Core tip: Less is known about the association between endogenous opioids and sexual function and behaviors in humans. There are mixed reports regarding the impact of oxytocin on sexuality and romantic relationships. The importance of physiological changes during sexual activity and how they can affect human relationships and the gaps in the literature highlight the need for high-quality research to extend our understanding of the hormonal physiology of sexual function and the role of endorphins and oxytocin in human sexuality.