Injecting men with a protein found in chocolate could boost sexual arousal, research suggests.
The protein kissepeptin, reportedly named after Hershey’s Kisses, is involved in cell signalling that ultimately trigger the production of fertility hormones.
Insufficient kissepeptin has been linked to a lack of menstruation in women, while a single injection has reportedly been shown to trigger ovulation.
Read more: How to enjoy sex during the menopause
With clear links to reproduction, scientists from Imperial College London set out to uncover whether the hormone could combat “sexual problems” like low libido in men.
Psychosexual disorders, defined as a lack of arousal or satisfaction while being intimate, are said to affect up to one in three people worldwide.
To learn more, 33 men aged between 18 and 34 were given an infusion of either kissepeptin or a placebo.
They were placed in an MRI scanner while sniffing the “widely recognised and validated female scent” Chanel No. 5.
The heterosexual men were also shown images of randomly-selected women’s faces.
During the experiment, the scientists monitored how the men’s brains responded to the visual and “smell” cues.
Results, published in the journal JCI Insight, suggest kisspeptin “enhanced attraction pathways in the brain” more than the placebo.
Upon viewing the female faces, those with a lower sexual quality of life had the biggest reaction.
“Psychosexual disorders have a major detrimental impact on wellbeing and can be highly distressing not only to those affected but also their partners,” said study author Dr Alexander Comninos.
“Despite the high numbers of people with these disorders, there are limited treatment options.
“Our study shows 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.
“Kisspeptin may actually enhance the processing of smell and facial attraction, which are often the first steps to sexual arousal”.
The scientists hope their results will lead to new therapies that tackle psychosexual therapies.
They add, however, “we still have a long way to go”.
Low libido is often linked to an underlying issue, like stress, depression or relationship problems.
It can also be a sign of reduced hormone levels or a health concern, such as cancer.
Treatment generally focuses on “self help” with the support of a psychosexual therapist.
Testosterone gels like Tostran and Testogel can boost sex drive among women, however, these are unlicensed.
Unlicensed medications are manufactured without marketing authorisation from the Medicines and Healthcare products Regulating Agency.
This is only granted when a medication is proven to be safe and effective.
While testosterone is considered a male hormone, women produce around three times more of it than oestrogen pre-menopause.
Falling levels during “the change” can make women desire sex less or find it unsatisfying.