Does Semaglutide Cause Cancer?

Every medication has the potential for unwanted effects. These might include interactions with other medications, minor side effects, or serious long-term health consequences. Semaglutide — a treatment for diabetes and chronic weight management — is no exception.

You may have heard that semaglutide (Wegovy, Ozempic, and Rybelsus) might raise the risk of cancer. There’s even an FDA black box warning about a possible link to a rare type of thyroid tumor. But how big is this risk? And does semaglutide increase the risk of other types of cancer? Here’s what you need to know.

Does semaglutide cause cancer?

Based on the research so far, no.

Two types of cancers have been studied closely: thyroid cancer and pancreatic cancer. Semaglutide carries a black box warning for thyroid cancer, but this is only based on rodent studies. There have also been concerns about pancreatic cancer. But these concerns are theoretical and based on concerns from older medications that work in similar ways, not research on semaglutide specifically. For both thyroid cancer and pancreatic cancer, there have been no large studies performed in humans that confirm any link to cancer.

That reassurance isn’t absolute, though. Medullary thyroid cancer, for example, is rare enough that even large studies may not catch a small change in risk. Semaglutide also hasn’t been around long enough to rule out health effects that take decades to show up. So, while there’s no established link between semaglutide and cancer, it’s still possible that one might be found in the future.

Despite all this, the best data around semaglutide and cancer shows that semaglutide might actually have the opposite effect: It could lower your risk for certain cancers. There are available studies that suggest that people taking GLP-1 medications have fewer cancers overall. This is likely because carrying excess weight raises the risk of several cancers in the first place.

Which cancers are semaglutide associated with?

Two types of cancer have been studied in connection with semaglutide: a specific type of thyroid cancer and pancreatic cancer. So far, the data doesn’t show a cause-and-effect relationship. In other words, available studies haven’t shown that semaglutide causes thyroid or pancreatic cancer. 

But these cancer types are very rare. So, it may be too soon to find a relationship. Ongoing research may provide more answers in the future.

How does semaglutide affect potential cancer risk?

Many cells in your body have GLP-1 receptors, so medications like semaglutide can affect many different organs. Rodents, in particular, have more GLP-1 receptors in their thyroid cells. When these receptors are activated, they trigger a cascade of changes that leads to C cell overgrowth. This might explain the increased cancer rates seen in rodents given semaglutide. 

In your pancreas, semaglutide increases the number of beta cells. These cells secrete insulin, which helps control blood sugar levels. This effect is one reason this medication helps people with diabetes. 

But even though semaglutide can increase growth of certain cells, researchers are still trying to understand semaglutide and its effects better. For now, there’s not enough information to know whether or how semaglutide affects cancer risk in humans.

Can semaglutide help prevent any type of cancer?

Semaglutide may help prevent certain types of cancer. Some types of cancer are more likely in people with excess body weight. Experts aren’t exactly sure why. They’re testing different theories, including whether losing extra body weight could also lower cancer risk.

A recent study supports this theory. Researchers found that people with body mass index (BMI) of 35 or higher who took GLP-1 medications had a 39% lower risk of weight-related cancers than people who didn’t take them. Interestingly, people who had bariatric surgery had only a 22% lower risk, even though they lost more weight. This could suggest that GLP-1 treatment might lower cancer risk in ways beyond just weight loss.

Of course, it’s still too early to say whether semaglutide or similar medications can prevent cancer. But expect more research to come in this area. 

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Written by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined clinical medicine with her passion for education and content development for many years. She is co-executive director at Nonclinical Physicians Network and has served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

Edited by:

Alex Eastman, PhD, RN

Alex Eastman, PhD, RN, is a California-based registered nurse and staff medical editor at GoodRx, where he focuses on clinical updates and Latino health.

Reviewed by:

Farzon A. Nahvi, MD

Farzon Nahvi, MD, is an emergency medicine physician and author of “Code Gray: Death, Life, and Uncertainty in the ER.” He works at Concord Hospital in Concord, New Hampshire, and teaches at the Geisel School of Medicine at Dartmouth.

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