LONDON — A new hormone injection could treat low sex drive in both women and men, according to researchers in the United Kingdom. A team from Imperial College London says kisspeptin can boost sexual responses in men and women suffering distress as a result of their low libido.
Two studies, both published in JAMA Network Open, show that giving patients kisspeptin can boost sexual responses in people who have hypoactive sexual desire disorder (HSDD) – a condition where patients experience psychological distress due to their low sexual desire. Women taking part in the trial reported feeling “more sexy” during the kisspeptin treatment.
HSDD affects up 10 percent of women and roughly one in 12 men worldwide. It can have “devastating” psychological and social impacts. Study authors explain that kisspeptin is a naturally-occurring hormone which stimulates the release of other reproductive hormones in the body. The team previously demonstrated that kisspeptin can enhance responses to sexual stimuli and boost attraction brain pathways independent of other reproductive hormones like testosterone in men with intact sexual desire. Now, they’re investigating the effects in women and men with low sexual desire for the first time.
The two clinical trials involved 32 pre-menopausal women between the ages of 19 and 48, and 32 men with HSDD. In both studies, researchers scanned participants using brain MRI imaging, as well as blood and behavioral tests. Taking kisspeptin improved sexual brain processing in both women and men. This resulted in positive boosts in each person’s sexual behavior compared to those who did not receive the injections.
The clinical trials are the first to explore the ability of kisspeptin to boost sexual pathways in people suffering distress from low libido. The researchers believe that the results provide the groundwork for kisspeptin-based therapies for people with HSDD.
“Low sexual desire can be distressing and so result in HSDD. This can have a major detrimental impact on relationships, mental health, and fertility. Even though it is relatively common, treatment options in women are limited, carry significant side-effects and in some cases can be harmful to even try. And unfortunately, these treatments have limited effectiveness. In men there are currently no licensed treatments and none on the horizon. Therefore, there is a real unmet need to find new, safer and more effective therapies for this distressing condition for both women and men seeking treatment,” says Dr. Alexander Comninos from the Department of Metabolism, Digestion and Reproduction at Imperial College London in a media release.
“Our two studies provide proof-of-concept for the development of kisspeptin treatments, as we provide the first evidence that kisspeptin is a potentially safe and effective therapy for both women and men with distressing low sexual desire,” Dr. Comninos continues.
“Additionally in men, we demonstrate that kisspeptin can have positive effects not only in the brain but also in the penis by increasing rigidity. Furthermore, kisspeptin was well-tolerated by both women and men with no side-effects reported, which is crucial from a drug development point of view. We now plan to take things forward to hopefully realize the potential of kisspeptin therapeutics in psychosexual disorders – sexual problems which are psychological in origin, such as unexplained low libido.”
“Our studies build on our previous work to assess the effectiveness of kisspeptin and its boosting effects in terms of arousal and attraction. It is highly encouraging to see the same boosting effect in both women and men, although the precise brain pathways were slightly different as might be expected,” adds Professor Waljit Dhillo, an NIHR Senior Investigator and co-senior study author.
“Collectively, the results suggest that kisspeptin may offer a safe and much-needed treatment for HSDD that affects millions of people around the world and we look forward to taking this forward in future larger studies and in other patient groups.”
The treatment creates more ‘happiness about sex’
During kisspeptin or placebo treatments, female participants underwent functional MRI scans while watching erotic videos and viewing male faces to see how these videos affected brain activity. Non-erotic exercise videos served as a control in the experiment. The team found that kisspeptin improved sexual and attraction brain activity in key brain areas in women.
Results also show that women suffering from distress due to low sexual function had greater kisspeptin-enhanced brain activity in the hippocampus — a key structure that scientists say plays a role in female sexual desire. Researchers found that the more kisspeptin activated the posterior cingulate cortex — another key behavioral brain area — when participants saw attractive male faces, the less sexual aversion the women had.
In the second study, 32 heterosexual men between 21 and 52 with HSDD underwent a similar study. However, the team also measured penile rigidity between January and September 2021. The study demonstrated that kisspeptin significantly boosted brain activity in the “sexual brain network,” while also increasing penile rigidity by up to 56 percent in comparison to taking a placebo.
Similar to the study with women, kisspeptin had greater effects in key brain regions in men who were more distressed by their low sexual desire. Psychometric analyses reveal that kisspeptin improved “happiness about sex” among men.
What do the patients say about the treatment?
“I got involved in the trial because I had previous problems with my sexual appetite and performance,” says a 44-year-old man named “Peter,” who took part in the trails.
“The issue had always been detrimental to sustaining relationships. I would often make excuses as to why my sexual appetite was low. For example, I would blame stress at work or tiredness as a reason instead of being honest. I had tried other performance supporting medication like Viagra. However, this proved ineffective as the issue was simply one of low desire. It was highly embarrassing and not something I felt able to talk to my previous partners about. I feared they would confuse it with lack of attraction to them,” the trial participant continues.
“I was keen to learn whether there was a solution to my problem and learn more about my condition.”
“I received the kisspeptin infusion in June 2021 and I noticed a difference in terms of my sexual desire. The week I had the kisspeptin infusion we conceived our son, who was born in March 2022. I had the best possible outcome as a result of the trial.”
“I also learnt a lot more about myself and my condition. I am really pleased to have contributed to this trial, which has been life-changing for me. I’m glad that others in a similar position could benefit from the treatment.”
“I took part in the trial as I was experiencing low sexual libido. Initially, I put it down to having small children and being exhausted as a result. However, this continued and started to impact my wellbeing. I wanted to see whether there was another reason for why I was feeling this way,” adds another trial participant and 43-year-old mom named “Eve.”
“I had two study visits in 2020 where I received the placebo and the kisspeptin infusions without knowing which one I was getting at the time. I did notice a bit of a difference once I received the kisspeptin infusion and it was fascinating to be part of the process,” Eve adds.
“I am glad that I took part in the study as many women wouldn’t like to admit they are experiencing this and may not seek help. I’m glad to know that kisspeptin could be a treatment option for other women.”
Dr. Comninos and Prof. Dhillo now plan larger studies in order to develop kisspeptin as a realistic treatment for both men and women dealing with sexual disorders.
South West News Service writer Stephen Beech contributed to this report.