Experts have sounded the alarm over a bizarre side effect that may be triggered by slimming jabs: a drop in sex drive.
Once aimed at diabetes patients, drugs like Mounjaro and Wegovy are now famous for bringing about rapid weight loss by reducing appetite—but it seems they’re also slimming down some users’ libidos, too.
The injections’ side effects have been widely discussed, ranging from nausea and constipation and, in the most severe cases, life-threatening organ damage.
Now, top psychologists have warned that the medication may cause users’ libidos to plummet because of how it impacts a certain brain chemical.
Such is the concern among jab users, that hundreds have taken to online forums sharing how the drugs altered their sex drive, warning others that it was the ‘price they paid for no longer being fat’.
The injections spurs weight loss by mimicking the actions of a hormone released by in the gut after eating—GLP-1.
As well as telling the pancreas to make more insulin, GLP-1 feeds back to the brain and makes us feel full—stopping patients from over-eating.
According to Professor Rachel Goldman, a clinical pyschologist at New York University, GLP-1 drugs target ‘the reward center in the brain’, which is why people experience ‘less food noise, fewer craving and less interest in alcohol use’.
Top psychologists have warned that the medication may cause libido to plummet because of how it impacts a certain brain chemical
She told PureWow: ‘It’s also why what might impact your sex drive.’
Dr Kent Berridge, a professor of psychology and neuroscience at the University of Michigan, also previously told MailOnline that having sex with a partner, thinking of having sex with them and seeing them would normally trigger sexual desire, ‘just like drug use triggers desire for drugs’.
‘But if you’re suppressing [dopamine activation] a little bit and cutting down those mountain peaks, sexual desire is a natural peak, so that would be plausible.
‘Now, how is it doing that? How is it suppressing dopamine systems? That we do not know,’ Dr Berridge said.
‘It may be partly acting right on the nucleus accumbens [the brain structure known for its role in pleasure, reward and addiction], because there are receptors there.’
One British study published last year in QJM: An International Journal of Medicine found new patients on the drug may experience cognitive changes in their decision-making, partly from the calorie deficit the drug induces, as well as the effects of GLP-1 on brain function.
‘This isn’t as far-fetched as it might sound,’ the researchers said.
Another 2024 study also suggested that obese men who were taking semaglutide, the active ingredient in Ozempic and Wegovy, were at a slightly higher risk of erectile dysfunction than men with obesity who weren’t taking the drug.
The researchers found that females between the ages of 20 and 59 who had sex less than once a week were at a 70 per cent increased risk of death within five years
However, they added that further research needs to be done to ‘understand possible underlying biologic pathways that result in sexual dysfunction side effects’.
But the phenomenon has become so common that forum users are even sharing how the drugs have slashed their libido.
In one Reddit forum with over 142,000 members, one user said: ‘Before we started with Mounjaro we had a low but regular sex life, that was manly slowed down by us both feeling not comfortable with our bodies.
‘Since Mounjaro we have developed in different directions: I feel comfortable with my body and sexy the first time in my life and I’m really horny all the time, while my wife has no sex drive at all—even though she looks marvellous.
‘She says she feels like don’t wanting sex at all since taking Mounjaro. So is the price for no longer being fat, the end of an active sex life?’
Another wrote: ‘Anyone else have a completely depleted sex drive?
‘Ever since I’ve been on Mounjaro—second month now—I’ve noticed that no matter what I genuinely do not feel anything.’
A third added: ‘I’ve been on Tirzepatide [the ingredient behind Mounjaro] since February and I definitely have a much lower sex drive than I used to.
‘It’s really unfortunate because I feel a lot more confident in my body now but generally just don’t have a desire to do anything.’
According to Professor Goldman, however, the drugs may not directly be the cause of the new cause of friction in relationships.
Instead, it is likely due to weight loss in general, which is ‘nothing new’, she said.
One 2018 Swedish study of post-bariatric surgery patients found that that bariatric surgery patients who were married were 41 percent more likely to get divorced, compared to people in the general population.
Rapid weight loss can affect hormone balance, as can a restricted diet, by reducing amounts of essential sex hormones testosterone and estrogen.
At least half a million NHS patients and some 15 million patients in the US are now thought to be using weight-loss jabs, which can help patients lose up to 20 per cent of their body weight in just a few months.
And the numbers using them privately are even higher.
The health service currently prescribes Wegovy to around 35,000 patients at specialist weight management clinics.
Mounjaro, meanwhile, has been available in similar clinics since March and as of this month, GPs are also able to prescribe it.
The drug warning also comes amid concern about a global sex crisis—or rather, lack of sex crisis.
One recent survey revealed more than a quarter (27 per cent) of Britons are now having less sex than they used to, with one in six admitting they haven’t got frisky the entire year.
According to a Royal College of Occupational Therapists poll of 2,000 adults last year, men and women typically only have sex 46 times a year — once every eight days.
But some have far less frequent amorous activity, with a tenth reported having sex less than once a year.
Last month, researchers at the University of Manchester, also revealed women who have sex at least once a week are the happiest in their relationships.
Their study showed that 85 per cent of women who had sex once a week described themselves as ‘sexually satisfied’.
In contrast, only 17 per cent of women who had sex less than once a month reported the same level of relationship bliss.
Sex and intimacy have been linked to several health benefits, including improving the condition of your heart, reducing stress and even boosting mental health.