The GLP-1 market is massive. A recent survey by health research group KFF reports that 1 in 8 US adults say they are currently taking a GLP-1 drug. This series asks health specialists about how the drug affects lifestyle factors, and its potential beyond weight loss.
“I don’t care for alcohol anymore,” your friend tells you during a patio dinner. She’s been taking a GLP-1 to manage her weight but has noticed a handful of downstream effects. “I was starting to feel nauseous after drinking, and lately I just don’t have a desire for it.”
We’re well aware of how GLP-1s impact metabolic health, but researchers are discovering that these medications not only affect appetite; they also influence the brain.
Dr. Ben Christiansen is a Neuropsychologist at Ogden Clinic. He discusses what’s happening inside the brain—the good, the bad, and what’s still unknown.
How GLP-1s Work
GLP-1 is a hormone that occurs naturally in the body. It helps regulate blood sugar, slows stomach emptying, and signals fullness. Medications like semaglutide and tirzepatide mimic or enhance these signals, helping people eat less and feel satisfied longer.
“GLP-1s are naturally occurring within us and most of us have enough endogenous GLP-1 as human beings,” explains Dr. Christiansen. However, modern foods and environments can make it difficult for those natural signals to guide our behavior. Highly processed foods, for example, are often engineered to be extremely rewarding, making it easier to overeat despite feeling physically full.
Reward-Seeking Behavior
One of the most noticeable effects people report while taking a GLP-1 medication is a reduction in "food noise"—the constant thoughts about food, cravings, or urges to eat.
Researchers believe this occurs because GLP-1 receptors are found not only in the digestive system, but also in areas of the brain involved in reward, motivation, and impulse control. By influencing these pathways, GLP-1s may reduce the rewarding feeling associated with certain foods. Less reward = a stronger signal to pause or stop eating.
This has led researchers to investigate whether GLP-1s could also help manage addictions and compulsive behaviors. Recent studies have shown promising results, including reduced alcohol consumption and lower rates of substance use among some patients taking GLP-1 medications.
Dr. Christiansen points to a recent BMJ study involving more than 600,000 veterans that explored the relationship between GLP-1 use and addiction outcomes. While the findings were encouraging, he cautions against viewing these medications as a standalone solution.
"Most participants are having good outcomes managing addiction with a GLP-1," he says. "But they also have found that removing the veteran from the situation that was leading to the addiction helped him or her ultimately break the habit. We ought to be looking comprehensively at managing addictions, because GLP-1s are not a panacea."
Mental Health Considerations
While many patients report positive experiences, researchers are also paying attention to mental health side effects.
"A big concern we're having is that in higher uses of GLP-1, we're seeing a higher level of anhedonia in people," says Dr. Christiansen.
Anhedonia refers to a reduced ability to experience pleasure from activities that were once enjoyable. Researchers are still working to understand why this may occur in some individuals. One theory is that because GLP-1s affect the brain's reward pathways, they dampen everything—from cravings to rewarding experiences.
For this reason, Dr. Christiansen believes mental health support should be part of the conversation.
"I believe that mental healthcare should be interconnected with GLP-1 usage," he says.
A Tool, Not a Cure
Experts increasingly emphasize that GLP-1 medications work best when paired with broader lifestyle and behavioral support.
Nutrition Support
Dr. Christiansen encourages patients to work with nutrition professionals who can help them build sustainable eating habits while their appetite is reduced. Because GLP-1 medications decrease hunger, it becomes especially important to prioritize protein, nutrient-dense foods, and healthy eating patterns.
Muscle Maintenance
He also stresses the importance of preserving lean muscle mass through adequate protein intake and resistance training. “Maintaining muscle is good for us in so many ways, from metabolism to longevity,” he says.
Therapy
For individuals struggling with binge eating, compulsive behaviors, or addiction, behavioral health support may also play an important role.
"GLP-1s are not a cure, they are a tool," says Dr. Christiansen. "Understanding the underlying root causes of compulsive behavior are the way to impact change long term."
---
As research continues, scientists are learning that GLP-1 medications influence much more than weight. By affecting appetite, reward pathways, and behavior, these medications may open new possibilities for treating obesity, addiction, and compulsive disorders. At the same time, experts agree that long-term success is most likely when medication is paired with nutrition education, physical activity, and appropriate mental health support.
Dr. Ben Christiansen is a Neuropsychologist practicing in Layton and Logan, Utah. His clinical focus covers traumatic and acquired brain injuries, neurodegenerative disorders, neurotoxins, and cognitive disorders. Learn more or schedule with Dr. Christiansen here.