An injection of a hormone found in chocolate was found to make men more excited when exposed to the smell of perfume – or images of women's faces.
The simple jab can increase the performance between the sheets of those who suffer from a low libido.
Known as & # 39; kisspeptin & # 39 ;, it is named in recognition of its discovery at Pennsylvania State University – the city where Hershey's chocolate kisses are made.
Senior co-author Dr. Alexander Comninos, of London Imperial College, said: "Psychosexual disorders have a major negative impact on well-being and can be highly distressing, not only for those affected, but also for their partners.
"Despite the high number of people with these disorders, there are currently limited treatment options.
"Our study shows that kisspeptin can increase attraction-related brain activity and, intriguingly, this stimulating effect is even greater in men with poor sexual quality of life."
Up to one in three men suffers from a sexual problem, such as low desire, which is more psychological than physical.
This can damage relationships and fertility. One of the most common is the loss of libido, or sexual desire, which is usually related to personal problems, stress or tiredness.
It can also be a sign of an underlying medical condition, such as reduced hormone levels – or without any of these problems.
Despite the high clinical burden, there are few treatments due to ignorance about brain processes. Kisspeptin was nicknamed Viagra of mind.
The study published in JCI Insight involved 33 heterosexual men aged 18 to 34 years who underwent magnetic resonance imaging (MRI) scans when feeling a popular fragrance and viewing female faces.
This particular perfume, Chanel No. 5, has already been shown to be associated with sexual arousal.
In addition, when seeing the faces, kisspeptin had a greater effect on men who had a lower quality of sexual life.
Now, the team hopes to conduct the first clinical trials in patients diagnosed with low libido.
They have already shown that kisspeptin improves the way the body processes sexual arousal. The latest results highlight its impact on gray matter.
Attraction is a fundamental process that triggers sexual arousal, sexual activity and, often, reproduction.
Comninos said: "This builds on our previous work, which identified a role for kisspeptin in sexual arousal.
"Now we find that kisspeptin can actually improve the processing of smell and facial attraction, which are usually the first steps towards sexual arousal.
"We hope that our growing understanding of how kisspeptin stimulates parts of the brain involved in attraction and arousal can lead to new ways of treating affected people. However, we still have a long way to go."
Kisspeptin is a natural chemical that stimulates the release of other reproductive hormones within the body.
The researchers wanted to see if this hormone can be used to stimulate regions of the brain that govern attraction in healthy young people with normal libido.
Senior co-author Prof Waljit Dhillo, based in the same lab, added: "Attraction is often the first step towards sexual arousal and it is encouraging to see that kisspeptin can also increase brain activity related to it.
"This new discovery helps us to better understand the brain activity of people with psychosexual disorders that can lead to therapeutic targets."
One in ten men in the UK is believed to have sexual problems, many suffering from a lack of libido caused by relationship problems, stress and anxiety.
This can cause problems for couples who try to have a child and are advised to have sex regularly throughout the month. Kisspeptin is expected to maintain the answer.
The team believes that this new vision may lead to new therapies to combat psychosexual disorders and plans to conduct further studies to explore this.
The discovery may also lead to better treatments for stress and depression.