GLP-1 drugs can do a lot more than treat obesity and diabetes, with a growing list of indications for conditions including heart disease, obstructive sleep apnea, kidney disease, and advanced liver disease.
Now, early-stage research has begun to suggest that GLP-1 drugs like semaglutide (Wegovy, Ozempic) and tirzepatide (Zepbound, Mounjaro) may reduce the risk of certain types of cancer and help prevent cancer from spreading after a diagnosis.
Scientists are still working to understand why GLP-1s might help fight cancer and how much protection these medications could possibly provide.
That doesn’t mean GLP-1s are cancer-prevention drugs. Experts agree there’s not enough evidence yet for a person to consider taking these medications solely to lower cancer risk.
Why Research on GLP-1s and Cancer Deserves Attention
Real-world studies presented at medical conferences this year — including one organized by ASCO (the American Society of Clinical Oncology) — have scientists feeling energized to further investigate the impact of GLP-1s on cancer.
“There were over a dozen abstracts at the ASCO Annual Meeting reporting GLP-1 benefit in multiple cancers,” says Elizabeth McDonald, MD, PhD, a professor of radiology and breast cancer researcher at the Hospital of the University of Pennsylvania in Philadelphia.
While some of these studies looked at cancers known to have a connection to obesity, others focused on cancers not classically associated with excess weight, she says.
Taken together, the research “deserves the attention of the general public because it appears to show protective benefits not only across multiple cancer types but also across the entire cancer continuum, from primary prevention to preventing progression after a cancer diagnosis to metastatic disease to decreasing recurrence to increasing survival,” Dr. McDonald says.
Treating Obesity May Lower Some Cancer Risks
Excess body weight is a known risk factor for several cancers, says Sun Kim, MD, an endocrinologist who specializes in type 2 diabetes, polyendocrine metabolic ovarian syndrome (PMOS), and obesity at Stanford Health in California.
The International Agency for Research on Cancer classifies 13 cancers as obesity-related:
- Colorectal cancer
- Endometrial cancer
- Postmenopausal breast cancer
- Gallbladder cancer
- Kidney cancer
- Liver cancer
- Esophageal cancer
- Ovarian cancer
- Pancreatic cancer
- Stomach cancer
- Multiple myeloma
- Meningioma
- Thyroid cancer
Obesity is linked to insulin resistance and chronic inflammation, both of which are likely to drive increased cancer risk, says Dr. Kim.
“When a person is insulin resistant, they have to make more insulin, and insulin can act as a growth factor for cancers in susceptible individuals,” she says. Chronic inflammation can also promote tumor growth.
Weight loss can improve insulin sensitivity and inflammation, which makes it reasonable to study whether GLP-1 drugs could lower cancer risk, Kim says.
GLP-1s May Lower Cancer Risk Through Numerous Pathways
A big question is whether any GLP-1 anticancer benefit comes mainly from weight loss, or whether these drugs may also have effects that go beyond weight loss itself.
A study published in 2025 found lower cancer risk among people taking GLP-1s than among people who had weight-loss surgery, even though the surgery group lost more weight, suggesting the medications combat cancer through multiple pathways, according to McDonald.
Researchers are focusing on a few possible explanations:
Starving the Cells All cells use sugar for energy, but abnormal cells may be more likely to grow and multiply when blood sugar, insulin, and insulin-like growth factor-1 (IGF-1) are high. GLP-1s help regulate blood sugar and improve insulin sensitivity, which may lower some of the signals cancer cells can use to grow.
Quelling Chronic Inflammation Obesity is often linked with long-term, low-grade inflammation, which can damage cells and promote tumor growth. GLP-1s have been shown to have anti-inflammatory effects, which may help create a less cancer-friendly environment in the body.
Direct Receptor Signaling Some tumors have GLP-1 receptors — the docking sites that GLP-1 drugs act on. There’s evidence that people whose tumors had higher levels of these receptors tended to live longer, especially people with breast cancer.
While this connection doesn’t prove GLP-1 drugs directly slow tumor growth, it supports the idea that GLP-1 signaling may be involved in how some cancers behave, says McDonald.
What the Latest Real-World Studies Show About GLP-1s and Lowered Cancer Risk
Most of the current evidence comes from large real-world studies. These studies can show patterns in thousands of people, but they cannot prove that GLP-1s caused the lower cancer risk.
Here’s what the research has found:
Lower Overall Cancer Rates in Adults With Obesity or Overweight A JAMA Oncology study compared over 43,000 adults who used GLP-1 drugs with a similar number of matched adults who did not. Overall cancer rates were lower in the GLP-1 group: 13.6 versus 16.4 cancers per 1,000 person-years.
The strongest lower-risk signals were for endometrial cancer, ovarian cancer, and meningioma (a type of brain cancer). Kidney cancer showed a possible increased-risk signal that needs longer follow-up.
Lower Short-Term Cancer Rates in Adults With Obesity but Not Diabetes An Annals of Oncology study compared people with obesity who started GLP-1s for weight management with people who received diet or exercise counseling.
After matching, the study included almost 162,000 adults and found a lower short-term incidence of obesity-associated cancers in the GLP-1 group over a median follow-up of two years. The individual-cancer analysis showed lower risk estimates for multiple myeloma, pancreatic cancer, endometrial cancer, colorectal cancer, thyroid cancer, and breast cancer.
Lower Breast Cancer Incidence in Women Undergoing Breast Imaging McDonald’s study included almost 112,000 women ages 45 to 80 with a BMI of 25 or higher who had breast imaging. Women who had taken a GLP-1 had a lower incidence of breast cancer than women who hadn’t taken the medication, even after researchers matched for age, race, ethnicity, BMI, breast density, and type 2 diabetes.
Less Progression to Stage 4 Disease in Some People Already Diagnosed With Cancer A study presented at the 2026 ASCO meeting looked at people with stage 1, 2, or 3 cancer who started either a GLP-1 drug or a DPP-4 inhibitor after diagnosis.
People with lung, breast, colorectal, or liver cancer who took GLP-1s were 38 percent to 50 percent less likely to progress to stage 4 disease.
It’s Still Too Early to Know if GLP-1s Can Slow or Prevent Cancer
The biggest limitation on what we know about GLP-1s and cancer risk is that most of the current studies are observational. In observational studies, scientists analyze existing data, trying to match subjects and factor in potential biases.
That kind of research is less conclusive than clinical trials that follow subjects over time to create new and theoretically more reliable data that can do more to prove cause and effect.
“There will always be unmeasured confounders in observational data — this is why a clinical trial is important to show causality,” says McDonald.
Kim is also cautious about drawing too much from the current data. “Most GLP-1 clinical trials have been too short to fully understand cancer development, which can take years,” she says.
There is also the possibility that the current research may be affected by bias, with studies showing benefits for GLP-1s and cancer more likely to be published, she adds.
Tried-and-True Cancer Prevention Methods Are Still Key
More studies are underway to better identify the impact of GLP-1s on cancer. For now, scientists recommend sticking to tried-and-true ways of keeping cancer risk as low as possible.
These strategies include:
- Getting to and staying at a healthy weight
- Eating a healthy diet
- Getting regular physical activity
- Keeping up with regular health checkups
- Following recommended cancer screening schedules
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