New studies have found that a supplement of ghrelin - the "appetite hormone" - increased the sexual activity of mice.

Ghrelin is a gastrointestinal hormone that is released from the stomach, and is involved in the stimulation of our appetite by activating the brain's reward system. Since the brain's reward system also motivates us to seek a partner and to have sex, a group of researchers at the Sahlgrenska Academy decided to investigate whether ghrelin may also affect sexual behaviors. 

The answer is: yes, at least in mice.

In the study, the researchers show that when mice receive a supplement of ghrelin, they increase their sexual activity and their efforts to find a partner. The effect is confirmed in a follow-up experiment, where mice that received a ghrelin inhibitor instead decreased their sexual activity.

"It is already known that ghrelin affects the reward mechanisms that are triggered by food, alcohol and other addictive drugs. Our study now shows for the first time that ghrelin also plays a role in natural reward mechanisms like sex," says Elisabet Jerlhag, researcher at the Sahlgrenska Academy.

The studies show that the effects of the ghrelin are conveyed via dopamine, which is a known messenger in the brain's reward system. The researchers' conclusion is that both ghrelin and dopamine regulate normal sexual behavior in mice.

"However, this does not mean that ghrelin fills the same function in humans. Finding out requires significantly more research in the area. But ghrelin inhibitors may potentially be a key to future treatments for sex addiction and sex abuse," says Jerlhag. 

Article: "The role of ghrelin signalling for sexual behaviour in male mice ", Addiction Biology.