Hormone Injection May Boost Brain Activity Associated With Attraction

Kisspeptin was found to trigger greater activation in attraction pathways in the brain in the trial involving 33 heterosexual men using MRI brain scans after the men smelled female perfume and when viewing female faces as compared to the placebo. 

“Psychosexual disorders have a major detrimental impact on wellbeing and can be highly distressing not only to those affected but also their partners. Despite the high numbers of people with these disorders,there are currently limited treatment options. Our study shows that kisspeptin can boost brain activity related to attraction and intriguingly this boosting effect is even greater in men with a low sexual quality of life,” said co-senior author Dr. Alexander Comninos of Imperial College London. 

"This builds on our previous work that identified a role for kisspeptin in sexual arousal. Now we have found that kisspeptin may actually enhance the processing of smell and facial attraction, which are often the first steps to sexual arousal. We hope our growing understanding of how kisspeptin boosts parts of the brain involved in attraction and arousal can ultimately lead to new ways of treating people affected. However, we still have a long way to go."

"Attraction is usually the first step to sexual arousal and it's encouraging to see that kisspeptin can also boost brain activity relating to this. This new finding helps us further understand the brain activity of people with psychosexual disorders which could lead to therapeutic targets,” said co-senior author Professor Waljit Dhillo also of Imperial College London.

1 in 3 people are affected by psychosexual disorders around the globe, with detrimental effects on quality of life, interpersonal relationships and fertility. Loss of libido is one of the most common complaints, and it is often linked to relationship issues, stress, fatigue, or tiredness but it can also be a sign of an underlying medical issue such as low hormone levels. Loss of libido can also occur without any of these issues, and limited understanding of brain processes governing psychosexual function has restricted the development of effective treatments. 

The hormone kisspeptin is naturally occurring and it stimulates the release of other reproductive hormones in the body. To investigate whether it can be used to stimulate regions of the brain that govern attraction in young healthy men with normal libido a randomized, double blinded and placebo controlled trial was conducted in which 33 healthy men between the ages of 18-34 were given infusions of either kisspeptin or a placebo. 

When the participants were placed in an MRI scanner and given perfume to smell and view female faces their brains were scanned to see how kisspeptin affected their brain responses to the faces and perfume; kisspeptin was found to enhance attraction pathways in the brain when viewing the female faces as well as when smelling the perfume as compared to the placebo. When viewing the female faces kisspeptin was also found to have a greater effect on attraction pathways in men who reported having a lower sexual quality of life. 

It is hoped that the new insight may eventually lead to new kisspeptin therapies that will help to combat psychosexual disorders, and the researchers have plans to carry out more investigation to further explore kisspeptin.