Dan Hunt, 35, of Barrie, Ont., began taking the weight loss drug Wegovy in March while on parental leave with his second child.
“The second week … I got hit like a Mack truck,” he said.
“I’ve had norovirus and I’ve had terrible seasickness and stuff like that, and neither of those compared to the second week of Wegovy.”
Along with debilitating nausea and vomiting, he experienced a severe dip in his mood.
“Sudden[ly I was] feeling very defeated … everything turns to doom and gloom. The best way I can describe it is, suddenly the day just seems dimmer,” he said.
“When I’m talking to [my wife] and all of a sudden I’m not happy talking to her — that’s jarring to me.”
Hunt is not alone in reporting such changes.
On the social media platform Reddit, dozens of users describe feeling emotionally stunted when they are on Ozempic, another popular GLP-1 drug.
“Mentally I feel like a zombie,” wrote one commenter.
Another said, “I have minimal passion for anything, very monotone and no enthusiasm.”
While data remain limited on this phenomenon — sometimes dubbed “Ozempic personality” — clinicians say it makes sense that GLP-1s could have unintended emotional effects.
GLP-1s impact the brain’s reward system, making them effective at regulating not only appetite but other forms of desire.
“It’s like a blunt instrument,” said Dr. Ashley White, a physician in Hamilton, Ont., who specializes in metabolic health.
“Anything where the brain has learned to experience that pleasure will be turned down.”
The pleasure knob
GLP-1 drugs were originally developed to treat Type 2 diabetes. But their use has quickly expanded far beyond diabetes care.
In 2021, Health Canada approved Wegovy for weight management. Mounjaro was approved for Type 2 diabetes in 2022 and has also been used off-label for weight loss. In 2025, Health Canada approved Zepbound for weight management.
Cheaper, generic GLP-1s became available in Canada in early 2026, and their uptake in Canada has been rapid.
A 2024 survey by Dalhousie University’s Agri-Food Analytics Lab suggested close to two million Canadians may already be using a GLP-1 drug for weight loss. The same survey found about seven million Canadians are considering taking them.
White says GLP-1’s effect on the brain explains how these drugs can affect people’s moods.
The brain’s reward system is largely driven by dopamine, a neurotransmitter that reinforces survival behaviours such as eating and seeking pleasure.
“When the human brain decides it needs food … it also could just be a desire to change the mood state, and it’s going to summon a neurotransmitter called dopamine, and it’s going to start pursuing food,” said White.
“We learn, over time, as we eat, what food feels really good in our minds and what food doesn’t … and that is the cycle of positive reinforcement that is the basis of basically all human learning.”
Dr. Peter Lin, a Toronto physician, noted on a recent podcast that GLP-1 drugs appear to amplify satiety signals while also modulating dopamine pathways. This potentially dampens reward responses linked to food but also other substances and experiences.
Lin described GLP-1s as a kind of pleasure knob, turning down reward signals across systems.
“Right now we have a big volume knob on your stereo — it turns down everything,” he said.
This feature could have some positive applications, such as treating addiction.
“For example, cocaine works by increasing dopamine by a lot,” Lin said on the podcast. “[I]f you’re taking a GLP-1, then that dopamine is cleared away very quickly, so there’s less reward, so you’re less interested in cocaine, and that means less cocaine addiction.”
But White also notes the drugs may need to be fine tuned over time. “In the future, we might have a few little knobs that you can adjust,” she said.
“We don’t want [GLP‑1s] to affect someone’s experience of childbirth, or their ability to … fall in love, or to maintain peer connections, or to … be excited about learning something new or watching their favorite band,” she said.
Coping mechanisms
Hunt’s chronic nausea and reduced ability to eat has affected his mood and presence at home.
“I’m anxious, and … that makes me less present in being a parent and a supportive partner,” he said.
“The kiddo’s crying, and I need to calm down his crying. But also I’m like, ‘I need to eat, I need to take care of this, I need to do this. And everything would just get cycling,’” he said, noting he is supposed to eat about 3,300 calories a day, but Wegovy makes this difficult.
“It’s not that I’m building resentment for my child. It’s that I’m worrying about building resentment for my child. And that takes away from the experience.”
White says that when GLP-1s blunt the reward response to food, patients can feel as though a key emotional regulator has been removed.
“If someone experiences a lot of reward from food … and all of a sudden they don’t have that reward available anymore … then they will experience [their negative] emotions more fully,” she said.
“Not only will they experience the negative [emotions] more fully, they will also have blunted positive emotion[s].”
She adds that this effect can be destabilizing for some patients, especially for patients with histories of substance use or trauma, where food or drugs can be a coping mechanism.
“When people are very reliant day-to-day on food for their joy … we take away a really, really important regulatory mechanism,” she said.
Emotional journey
Dr. Stephen Glazer, an obesity medicine specialist and medical director of the bariatric medical and surgical program at Humber River Hospital in Toronto, cautions against over-interpreting reports of mood or personality change due to GLP-1s. Obesity is itself an emotionally complex disease, he notes.
“Obesity is a chronic disease. It’s unremitting, relapsing, challenging and emotionally draining,” he said.
He adds that changes in appetite and food pleasure may reflect multiple overlapping factors, including nausea and early satiety.
“Is it possible that interest in food and pleasure is diminished? Yes … maybe [eating becomes] more mechanical than emotional,” he said.
“People who are chronically nauseous … may have depressed moods — not necessarily depression. When someone’s chronically nauseous … nothing is going to be good.”
Still, Glazer says these experiences warrant attention rather than dismissal. “We need to continue to explore and investigate and listen to our patients,” he said.
White agrees. She cautions against treating negative symptoms as a reason to abandon therapy, arguing for more individualized dosing and monitoring. “The only way to do that is to be really thoughtful about your dosing strategy … and to get continuous feedback,” she said.
Hunt has not dropped much weight while on Wegovy, and has been unsettled by the experience. But has not given up on the drug yet.
“I still think that I’m optimistic for what the medication is going to do for me,” he said. “I’m hoping I’ve weathered the storm, and that it’s only up from here.”
