GLP-1 Weight Loss Drugs and Cancer: Is There a Link?

Medications like Ozempic, Wegovy, and Mounjaro have changed how doctors treat obesity. Originally developed to manage diabetes, these drugs, known as GLP-1 receptor agonists, have shown remarkable success in helping people lose weight. With weight loss came unexpected benefits- improvements in blood pressure, heart health, liver function, and kidney health among people taking these medications. 

As use of these medications has grown in popularity, so have questions about safety, especially when it comes to cancer. Do GLP-1 weight loss drugs increase cancer risk, lower it, or have no effect at all? 

Based on current evidence, the answer is reassuring and increasingly hopeful. 

Obesity and cancer  

Excess body weight is one of the most impactful modifiable risk factors for cancer. According to the American Cancer Society, more than 40 percent of cancer deaths among U.S. adults may be linked to lifestyle factors that can be changed, including excess body weight. People with overweight or obesity have a higher risk of developing at least 13 cancers, including postmenopausal breast cancer, colorectal cancer, endometrial cancer, pancreatic cancer, liver cancer, and kidney cancer. 

“Obesity affects cancer risk in several biological ways,” says Dawn L Hershman, MD, MS, FASCO, Witten Family Professor of Medicine and deputy director of the Herbert Irving Comprehensive Cancer Center at Columbia University. “It can raise estrogen levels, which fuel certain hormone-related cancers, increase insulin and insulin-like growth factors that help tumors grow, and drive chronic inflammation that creates an environment where cancer is more likely to develop and spread. That’s why weight management plays such an important role in cancer prevention.” 

Early concerns of using GLP1s 

Early in the widespread use of GLP-1 drugs, some studies raised concerns about a possible link to thyroid or pancreatic cancer. More recent and more rigorous research has not supported a causal relationship. 

Large meta-analyses have found no increased risk of gastrointestinal cancers, including colorectal, pancreatic, liver, or gallbladder cancers, among people taking GLP-1 receptor agonists. In the case of thyroid cancer, experts believe early findings were likely due to detection bias rather than a true increase in risk.  

That said, GLP-1 drugs are still prescribed carefully, and physicians take a thorough history for each potential patient to better understand their potential risk factors.  

Can GLP-1 drugs lower cancer risk? What we know so far. 

Because GLP-1 medications lead to meaningful weight loss, researchers have begun studying whether they might also reduce the risk of obesity-related cancers. Several large studies suggest this may be the case. 

GLP-1 medications help regulate appetite, blood sugar, and metabolism. By making people feel full sooner and longer, they can lead to significant weight loss- often more than what lifestyle changes alone can achieve. 

In nationwide research involving people with type 2 diabetes, patients taking GLP-1 receptor agonists had lower rates of many obesity-related cancers compared with those taking other diabetes medications. A more recent observational study of more than 170,000 people with diabetes and obesity found that GLP-1 use was associated with a modest reduction in risk across 14 obesity-related cancers, along with a lower risk of death from all causes. 

“While these findings do not prove that GLP-1 drugs directly prevent cancer, they strongly suggest that treating obesity may help lower cancer risk over time,” says Dr. Hershman.

Some research has also looked at cancer outcomes among people already diagnosed with cancer. In a large analysis of more than 6,800 colorectal cancer patients across the University of California health system, those taking GLP-1 medications were less than half as likely to die within five years as patients who were not taking the drugs. 

While observational studies like this cannot establish cause and effect, they add to growing evidence that weight management may play an important role not only in cancer prevention, but also in survivorship. 

Long-term health, and limitations 

GLP-1 weight loss drugs are not cancer prevention medications, and they are not designed to be taken forever. Many people regain weight after stopping them, which may limit their long-term impact on cancer risk. 

For many patients, however, these medications can serve as a helpful starting point. By helping people lose weight, GLP-1 drugs may make it easier to increase physical activity, improve metabolic health, and sustain lifestyle changes that are known to reduce cancer risk. In this way, they can support, rather than replace, long-term prevention strategies. 

GLP-1 medications are also being studied for benefits beyond weight loss, including improved heart and kidney health and possible effects on addiction-related behaviors. However, access remains a challenge. These drugs are expensive, insurance coverage is inconsistent, and supply shortages have made them difficult to obtain, even for patients with clear medical needs. 

Weight management is also important after a cancer diagnosis. In a recent study of breast cancer survivors , patients who received weight management therapy had lower rates of cardiovascular events than those who did not.  

What this means for you 

Current evidence suggests that GLP-1 weight loss drugs do not increase cancer risk and may help reduce the risk of several obesity-related cancers by addressing one of cancer’s most important modifiable drivers: excess body weight. While more research is needed (particularly in people without diabetes and over longer follow-up periods), these medications are reshaping conversations about obesity, cancer prevention, and survivorship. 

For anyone considering GLP-1 medications, it’s important to make the decision together with a healthcare provider. A personalized approach takes into account your overall health, medical history, potential risks and benefits, and long-term goals for weight management and well-being.