What Do We Know About Weight-Management Treatments Like Ozempic?
Author: Ahmad Mohammad, PhD student, University of Toronto | Editors: Romina Garcia de leon
Published: October 17th, 2025
What are GLP-1 agonists, and how do they work in the body?
Glucagon-like peptide-1 (GLP-1) agonists (which are in commonly known drugs such as “Ozempic”) are medications that mimic the behaviour of a natural hormone called GLP-1, which is released in the gut after we eat. Through its signalling, this hormone slows down how quickly the stomach empties and communicates with the brain to help us feel full sooner and longer. GLP-1 plays a crucial role in keeping blood sugar levels stable throughout the day, which is why it’s an important target for diabetes treatment. Because of these combined effects, long-lasting GLP-1 agonists (drugs that can make the body feel as though GLP-1 is there longer than it truly is), reduce appetite, help control blood sugar, and ultimately support weight loss. They were originally designed for people with type 2 diabetes but are now widely used as a tool for weight management as well.
People are using GLP-1 agonists as a “miracle weight loss drug.” What happens when people stop using these drugs? Are there any long-term effects on metabolism?
GLP-1 medications can lead to significant weight loss, especially when combined with healthy habits such as exercise. When people eventually stop taking the drug, however, many find that their appetite returns, and they begin to regain the weight they lost as they continue to satisfy their appetites. This is because the medication was doing a lot of the work in helping regulate feelings of hunger so when the medication is no longer there, people need to rely on their own natural hunger levels.
As for long-term effects on metabolism, we still have a lot to learn. While GLP-1 agonists are generally safe and effective, we do not yet fully understand what happens to the body years after stopping the treatment as the increase in its popularity has been very recent and long-term studies have yet to be conducted. That is why medical supervision and sustainable lifestyle changes remain important, even for those seeing great results on these drugs.
What do we know about GLP-1 (and GLP-1 agonists) and brain health?
GLP-1 doesn’t just act only on the gut and pancreas as was originally thought. It also travels to the brain, where it can reduce inflammation, protect brain cells, and possibly support memory. In fact, GLP-1 can also be produced directly in the brain to exert these beneficial effects more directly to neurons in times of need. Recent research suggests that GLP-1 may even be able to help slow down or prevent changes in the brain that are linked to Alzheimer’s disease. While the exact pathways underlying this effect remain unclear, several theories have been proposed and warrant further investigation.
GLP-1 has been shown to support brain health through two pathways. First, GLP-1 produced in the brain itself could act in a protective manner to limit degradation. Second, by helping reduce obesity, a major risk factor for Alzheimer’s disease, GLP-1 may be indirectly lowering risk for degradation. Together, these routes highlight GLP-1’s potential role in protecting the brain in various ways. The discovery that GLP-1 influences brain health is exciting because it means a medication originally created for diabetes might also help protect the brain and support healthy aging in certain populations. Scientists are still working to understand exactly how it works, but the potential for brain health benefits is a promising new direction the field is beginning to investigate.
Can you tell us what you’re researching?
My research focuses on how hormones like GLP-1 and estrogens affect the brain, especially in people who are at risk for Alzheimer’s disease. I’m studying a new treatment that combines both of these hormones into one therapy, and I’m testing how it works in mice that carry genes linked to Alzheimer’s disease risk. I look at how this treatment affects memory, brain inflammation, and the growth of new brain cells. I’m also exploring whether it works differently in males and females, and whether diet plays a role in how effective the treatment is. In particular, I’m interested in the effects that this combination drug can have in mice consuming a high-fat, high-sugar diet, commonly referred to as a western diet. The goal is to better understand how we can use these hormones to protect the brain in the people who need it most.
Why is your research meaningful and what can we take away from it?
Alzheimer’s is a devastating disease that affects millions of families worldwide. Females are especially at risk, yet they are often overlooked in medical research. My work aims to change that by studying how biological sex, hormones, and metabolism can work together to shape brain health. I hope this research will lead to more personalized and effective treatments that take individual differences into account. What I find most meaningful is that this work brings together the body and the brain. It reminds us that brain health is connected to everything we do, from what we eat to how our hormones function. The more we understand those connections, the better we can protect our minds as we age.
