GLP-1 Medications: More Than Weight Loss

GLP-1 medications such as semaglutide and liraglutide were originally developed to treat type 2 diabetes and are now widely used for weight management. They mimic a natural hormone called glucagon-like peptide-1 (GLP-1), which helps regulate blood sugar, slows stomach emptying, and reduces appetite. In addition to these metabolic effects, GLP-1 signaling also reaches the brain, where it influences areas involved in reward, stress, and energy balance.

Emerging Uses Beyond Diabetes and Obesity Researchers are increasingly studying GLP-1 medications for their effects on the brain. Early evidence suggests that these medications may help regulate craving, compulsive behavior, inflammation, and mood. In preclinical studies, GLP-1 receptor activation has been shown to reduce drug and alcohol seeking behavior. Early human data also suggest that GLP-1 medications may reduce alcohol craving and intake. In addition, there is growing interest in their role in depression, particularly in patients who also have metabolic dysfunction or inflammation. These uses are still emerging and are not yet considered standard psychiatric treatments.

How Might GLP-1 Medications and Ketamine Work Together?

Ketamine and GLP-1 medications appear to act on complementary brain systems. Ketamine produces rapid antidepressant effects by increasing neuroplasticity, or the brain’s ability to form new connections, through glutamate signaling, AMPA activation, and downstream pathways involving brain-derived neurotrophic factor (BDNF) and mTOR. GLP-1 medications, on the other hand, may help reduce background “noise” in the system by lowering inflammation, improving metabolic function, and stabilizing reward signaling. In simple terms, ketamine may help the brain “reset,” while GLP-1 medications may help create a more stable environment that allows those changes to last.

What This Could Mean for Depression and Substance Use Disorders

In major depressive disorder, particularly in patients with treatment-resistant symptoms, anhedonia, or metabolic dysfunction, this combination may offer complementary benefits. GLP-1 medications may improve energy regulation and reduce inflammation, while ketamine enhances neuroplasticity, potentially improving both response and durability of treatment. In substance use disorders, GLP-1 medications may reduce craving and reward-driven behavior, while ketamine may support cognitive flexibility, emotional processing, and the ability to make lasting behavioral changes. Together, these treatments may address both the biological drive to use substances and the psychological capacity to change patterns of behavior.

Important Safety Notes

GLP-1 medications commonly cause side effects such as nausea, reduced appetite, constipation, or diarrhea, particularly when first started or when the dose is increased. Ketamine may cause temporary dissociation, dizziness, nausea, and increases in blood pressure. When these treatments are used together, timing and monitoring are important. These therapies should only be used under the guidance of a licensed clinician who is considering the full medical and psychiatric picture. The use of GLP-1 medications for psychiatric conditions remains off-label and is an evolving area of research.