Researchers are launching a major investigation into whether popular weight loss drugs like semaglutide (Wegovy, Ozempic) and tirzepatide (Zepbound, Mounjaro) could help prevent cancers linked to obesity. Dr. Kristin Altwegg, a fellow at the University of North Carolina at Chapel Hill, will spend the next three years examining how these medications affect early cancer development pathways, particularly in breast, endometrial, and colorectal cancers .

Why Are Researchers Studying Weight Loss Drugs and Cancer Risk?

The connection between obesity and cancer is well established. Research over the past three decades has shown that being overweight or obese increases the risk of at least 13 types of cancer . Since GLP-1 medications can help people lose between 15 and 20 percent of their body weight when combined with lifestyle changes, scientists are asking a logical question: could these drugs also lower cancer risk ?

The timing matters. Nearly 18 percent of Americans have used GLP-1 drugs for weight loss, making them among the most widely used medications in the country . Yet there simply hasn't been enough time for researchers to fully assess their long-term impact on cancer development. Some early data suggests that people living with overweight, obesity, or type 2 diabetes may experience reduced cancer incidence while using GLP-1 medications, but the mechanisms behind this potential benefit remain unclear .

What Exactly Will This Research Examine?

Dr. Altwegg's fellowship will use a dual approach, combining laboratory studies with research in people undergoing medically supervised weight loss. Her team will monitor several biological markers and signaling pathways that may explain how these drugs could influence cancer development .

The research will focus on understanding whether GLP-1 medications work directly on cancer cells or indirectly through their ability to improve overall metabolic health via weight loss. As Dr. Altwegg explained, "We have seen in early research that treatment with GLP-1 could possibly prevent cancer from developing, but this is still experimental. Now how it works, we don't know yet. One of the key questions is whether these drugs act directly on the cancer cells or indirectly through their ability to improve overall metabolic health via weight loss" .

Dr. Altwegg

"We have seen in early research that treatment with GLP-1 could possibly prevent cancer from developing, but this is still experimental. Now how it works, we don't know yet. One of the key questions is whether these drugs act directly on the cancer cells or indirectly through their ability to improve overall metabolic health via weight loss," said Dr. Kristin Altwegg.

Dr. Kristin Altwegg, AICR/WCRF Marilyn Gentry Fellow at the University of North Carolina at Chapel Hill

How Will Researchers Measure These Effects?

The study will track several biological signals and hormones that may explain any cancer-prevention benefits. One key focus is leptin, often called the satiety hormone, which is produced by fat cells and tells the brain to reduce food intake when fat stores are high . By examining how GLP-1 drugs affect leptin and other metabolic signals, researchers hope to understand whether reducing fat mass can decrease the signals that cancer cells use to grow rapidly .

The research will examine three specific areas:

• Immune Surveillance: How the body's immune system responds to potential cancer cells when taking GLP-1 medications alongside weight loss.
• Hormonal Signaling: Changes in hormones like leptin and other metabolic messengers that may influence cancer cell growth and development.
• Biomarkers of Cancer Development: Early warning signs and biological markers linked to carcinogenesis, the process by which cancer develops.

In the laboratory, Dr. Altwegg will use animal models and advanced multi-omics approaches, which examine genes, proteins, and metabolites simultaneously, to uncover mechanisms and biomarkers that may explain any observed benefits of GLP-1 medications .

What About Muscle Loss During Weight Loss?

An important secondary focus of the research involves examining whether strength training alongside GLP-1 drugs can preserve muscle mass and improve overall health outcomes . This matters because rapid weight loss can sometimes lead to loss of muscle tissue, not just fat. By studying how exercise combined with these medications affects body composition, researchers hope to optimize the health benefits of weight loss treatment.

Dr. Altwegg's primary goal is straightforward: "My primary goal is to reduce cancer incidence by promoting healthy lifestyle cornerstones: diet and exercise," she stated . This three-year fellowship, funded by the American Institute for Cancer Research, represents one of the first systematic attempts to understand whether these blockbuster weight loss drugs could have cancer-prevention benefits beyond their well-documented effects on weight and blood sugar control.

"My primary goal is to reduce cancer incidence by promoting healthy lifestyle cornerstones: diet and exercise," said Dr. Altwegg.

Dr. Kristin Altwegg, AICR/WCRF Marilyn Gentry Fellow at the University of North Carolina at Chapel Hill

The research comes at a critical moment. With GLP-1 medications becoming increasingly common, understanding their full health impacts, both positive and potential risks, is essential for patients and doctors making treatment decisions. While the results won't be available for several years, this work represents an important step toward answering one of the most pressing questions in modern medicine: can the same drugs that help people lose weight also help prevent cancer ?