They are designed to treat type 2 diabetes and correct the metabolic error that sets patients on the path to fatal heart disease.
But it didn’t take long before researchers noticed an unusual side effect of the drugs: people lost a surprising amount of weight. And fast.
The blockbuster drugs, including Ozempic, Mounjaro and Zepbound, are being rolled out today to millions of people who need to lose weight to improve their health – and appear to be causing other unexpected effects.
Some patients have reported a dulling of emotions and even thoughts of suicide, while others have reported declining libido and decreased sensation during sex.
Some have seen it also cure addictions. People who consistently drank a few drinks every night found that they had no desire to drink alcohol while taking the medication. Others noticed that their desire to splurge on random items in the stores had also diminished.
Now experts who spoke to DailyMail.com have revealed a fascinating new explanation for these wide-ranging, strange symptoms. They say it all has to do with the drug’s impact on a master brain chemical that controls virtually all human behavior.
This means that it is entirely possible that injecting Ozempic can change your entire personality.
TikToker Ashley Raibick (left) said taking semaglutide for weight loss sent her libido to an all-time low, saying “nothing turned me on.” Karen Ramirez (right) posted on TikTok telling DailyMail.com that Ozempic ‘disgusted’ her with alcohol
Ozempic and its sister drug Wegovy work by causing the body to bind to a receptor called glucagon-like peptide-1 (GLP-1), a protein that triggers the release of hormones in the brain that keep the stomach full and telling the body to stop eating and avoid cravings
The brain chemical at play is dopamine, responsible for a range of essential functions including feelings of reward and pleasure, as well as motivation and exercise.
It is also involved in fueling our emotional and physical cravings for food.
Dr. Kent Berridge, a professor of psychology and neuroscience at the University of Michigan, said this explains why suppressing hunger pangs also curbs cravings for other vices, such as alcohol, cigarettes or drugs.
This is because both addictive substances and foods activate the same dopamine signals and reward learning areas in the brain.
‘The craving for addictive drugs is also increased by hunger,’ Dr Berridge told DailyMail.com.
‘When researchers try to teach animals to administer cocaine themselves, they often keep them hungry for a while because this helps them learn.
‘Hunger is specific to food, but it’s more general than that: it activates cravings for many things.
“When you’re hungry, the motivational value of things, even those that aren’t food, seems to increase,” he added.
Ozempic – which works by mimicking GLP-1, a naturally occurring hormone that tells the brain it is full – can dampen this effect by making a person feel satisfied for longer.
By suppressing the activation of dopamine, the drugs suppress food cravings and possibly drug and alcohol cravings as well.
“Satiety may not only reduce cravings for food, but possibly other things as well,” said Dr. Berridge.
GLP-1 drugs too make you feel less hungry overall by feeling full more quickly due to delayed emptying of the stomach, Dr. Sue Decotisa weight-loss doctor from New York City, to DailyMail.com.
But GLP-1 drugs appear to modulate motivational dopamine systems in a way that doesn’t completely dampen cravings. Patients still want to eat, but eventually don’t eat as much as before.
One possibility is that the cravings are still there, but the medication has just made them less intense, Dr. Berridge said.
“That would be one possibility – taking away certain cravings, and those are the ones that are problematic when you’re trying to lose weight or when someone is trying to stop taking drugs,” he said.
Some patients taking GLP-1 medications have also noticed that their desire to do things like masturbate and have sex with their partner is significantly reduced.
A decrease in libido is “conceivable,” Dr. Berridge said. Having sex is a natural desire, and so if you suppress it reward trajectory could lead to a little, this could lead to a reduced sex drive.
Having sex with a partner, thinking about sex with him or her and seeing him would normally arouse sexual desire, he said, “just as drug use arouses desire for drugs.”
‘But if you suppress dopamine activation a bit and cut off the mountain peaks, sexual desire is a natural peak, so that would be plausible.
‘How’s that going? How does it suppress dopamine systems? We don’t know,” Dr. Berridge said.
‘It may, in part, act directly on the nucleus accumbens (the brain structure known for its role in pleasure, reward and addiction), because that is where receptors are located.’
Other theories are that the GLP-1 drugs’ indirect effects on hormones could be causing the changes in libido.
Rapid weight loss can affect hormone balance, just like a restricted diet, by reducing the amounts of essential sex hormones testosterone and estrogen.
Ozempic users have previously told DailyMail.com that the drug has stopped them craving alcohol
Henry Webb, from North Carolina, completed a two-month Wegovy course after reaching his weight goal. He used to consistently drink a few drinks in the evening, but said, “I didn’t feel like it because of the medication.”
Could an increase in sex drive due to GLP-1 drugs be possible?
“That doesn’t really fit the usual pattern,” Dr Berridge said. However, he suggested that it is possible that an increase in sexual desire indicates that patients are trading one animal instinct for another.
Yet another theory from concerned experts is that GLP-1 drugs can suppress dopamine so much that it actually leads to depression and even thoughts of suicide.
The FDA has received hundreds of reports of suicidal thoughts and depression from patients taking weight-loss drugs since 2010, as well as dozens of deaths “by suicide or suspected suicide.”
Patients included a mother of four who said she felt like she no longer wanted to be here, and a nurse who wanted to shoot herself.
The idea that semaglutide could lead to bad mood is “not impossible,” Dr. Berridge said.
This is due to a phenomenon called anticipatory anhedonia, he said, in which patients are unable to predict the future experience of pleasure, but also have lower motivation to take action toward achieving pleasure.
‘There have been cases in the past called anhedonia, such as in depression and schizophrenia… where ultimately it turned out not to be a loss of pleasure, but a loss of wanting pleasure.
‘Pleasure’ still gets the normal ratings, but nothing has value in life, and that’s a problem.”
“If (Ozempic) were to cause this kind of problem, I would expect it to be like this: evolution rather than real loss of fun.”
It may be that the person taking Ozempic was depressed before starting the medication, he said.
The European Medicines Agency recently said there is no evidence of a causal link between Ozempic and suicidal thoughts. The FDA came to a similar conclusion in January.
Dr. Decotiis, on the other hand, believes that Ozempic does indeed reduce depression.
“I think it regulates dopamine: it can increase it and it can decrease it, but basically it keeps it in a stable range.”
“I’ve seen a lot of reversal of depression in patients because when you enhance the action of dopamine, you really reduce depression, anxiety, compulsive behaviors like gambling and drinking, and all those things, even humans don’t do that anymore.” need them to start doing that,” she said.