But other recent studies suggest that GLP-1s can improve survival among some people diagnosed with cancer.

Among older adults with cancer and type 2 diabetes, taking the medication was associated with lower death rates, according to findings published in July 2025 in JAMA Network Open.

“That’s sort of opened a new avenue for us to explore the GLP-1 use in that special population,” said Serena Guo, a professor at the College of Pharmacy at Purdue University, who was a co-author of the study.

The drugs could also be helpful for patients with colon cancer. A study of more than 6800 people found that those who were using GLP-1s had less than half the five-year mortality rate compared with non-users, according to results published in November in the peer-reviewed journal Cancer Investigation.

The findings were consistent when researchers adjusted for demographics, other illnesses and the severity of the patient’s colon cancer diagnosis, said Raphael Cuomo, a professor and cancer researcher at the UC San Diego School of Medicine and the study’s author. He noted that people who were obese and taking GLP-1s appeared to benefit “quite a lot more” with regard to lowered death rates compared with patients who were within normal weight ranges.

“In this case, we’re seeing that these drugs are having a potentially pretty powerful effect,” he said. “Now, this does need to be validated in randomised trials so we can be certain about whether or not these are having anticancer effects or there are other mechanisms at play. But this is very promising evidence that these drugs can be very beneficial for patients with colon cancer.”

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How GLP-1s could help with cancer

The ability of GLP-1s, which were developed to treat type 2 diabetes, to help people lose weight is one way that the drugs could have benefits for cancer, experts said. Obesity is a major risk factor for many types of cancers.

“There’s a myriad of ways in which obesity in general contributes to cancer risk,” Shen said. If you’re able to modify your amount of body fat, also known as adipose tissue, “then theoretically you should be modifying cancer risk.”

GLP-1s could also be helping by decreasing diabetes risk and reducing inflammation, which can contribute to the development of cancers, she said.

Research is ongoing to better understand what GLP-1 drugs might be doing in people with cancer.

Scientists at Dana-Farber Cancer Institute in Boston, for instance, are studying the medication’s effect on liposarcoma, a type of cancer that starts in fat cells.

“This rare cancer, liposarcoma, gives us a unique opportunity to study what GLP-1 drugs do to cancer cells themselves,” said Erica Pimenta, a physician-scientist who is leading research into whether the weight-loss medications could be a pathway for treating liposarcoma.

Early studies showed that when GLP-1 drugs were administered to the tumour cells, researchers saw hints that the cells were “turning on or reprogramming themselves to behave more like a normal fat cell”, Pimenta said. There is interest, she added, in seeing if this work in liposarcoma can be applicable to other cancers.

In the meantime, experts urged people not to rush to start taking GLP-1 medications without consulting with healthcare providers.

“The decision to start one of these is not something that should be taken lightly,” Cuomo said. “These are long-term regimens, they’re expensive, and they can have side effects.”

It’s also important to keep in mind that using the medicine should be paired with healthy lifestyle habits, such as eating well and staying active.

“These GLP-1s aren’t Band-Aids as fixes for everything,” Shen said.

The Washington Post