Drugs originally prescribed for diabetes and weight loss may also help reduce the risk of colon cancer, according to new research that is drawing attention from oncologists and public health experts alike. A large real-world study has found that people taking popular GLP-1 drugs such as Ozempic and Wegovy were significantly less likely to develop colon cancer compared to those using aspirin, long considered a preventive option for the disease.

The findings, scheduled to be presented at the American Society of Clinical Oncology (ASCO) meeting in San Francisco, suggest that patients on GLP-1 receptor agonists had a 36 per cent lower risk of colon cancer than those taking aspirin. The study was led by Dr. Colton Jones, a hematology and oncology fellow at the University of Texas Health Science Center at San Antonio, who noted that while aspirin has shown modest cancer-prevention benefits, its long-term use is often limited by the risk of bleeding.

“GLP-1 receptor agonists, now widely prescribed for diabetes and obesity, may offer a safer option for both metabolic control and cancer prevention,” Dr. Jones said, highlighting the growing interest in the broader health benefits of these drugs beyond weight management and blood sugar control.

Colon cancer remains one of the most common and deadly cancers worldwide. In the United States alone, an estimated 150,000 people were diagnosed with the disease in 2025, and more than 50,000 died from it. Against this backdrop, any intervention that can meaningfully reduce risk has major public health implications.

GLP-1 drugs work by mimicking the glucagon-like peptide-1 hormone, which helps regulate insulin levels, lower blood sugar, suppress appetite and slow digestion. The most widely known drugs in this class include semaglutide, marketed as Ozempic and Wegovy, and tirzepatide, sold under brand names such as Mounjaro and Zepbound.

For the study, researchers analysed health records of more than 281,000 people from a large commercial healthcare database. About half of the participants were taking GLP-1 drugs, while the rest were on aspirin. The GLP-1 group was followed for an average of six years, compared to around five years for those using aspirin.

The protective effect was even more pronounced among individuals considered at higher risk for colon cancer due to personal or family history. In this group, GLP-1 users showed nearly a 42 per cent reduction in risk. Researchers also observed that people taking GLP-1 drugs experienced fewer serious side effects such as kidney damage, stomach ulcers and gastrointestinal bleeding, which are commonly associated with long-term aspirin use. However, gastrointestinal complaints like diarrhoea and abdominal pain were more frequent among GLP-1 users.

Despite the promising results, experts caution against overinterpreting the findings. The absolute benefit for an individual remains small, with data suggesting that more than 2,000 people would need to take a GLP-1 drug for one person to avoid colon cancer. Still, with nearly 6 per cent of Americans already using these medications, researchers estimate that as many as 20 million people may already be gaining some degree of cancer risk reduction.

When individual drugs were analysed, only semaglutide, liraglutide and dulaglutide showed a statistically significant protective effect. Tirzepatide did not demonstrate the same level of impact in this analysis, underscoring the need for further drug-specific research.

Cancer specialists say the findings open an intriguing new chapter in cancer prevention. Dr. Joel Saltzman, vice chair of regional oncology at the Taussig Cancer Center at the Cleveland Clinic, described the results as encouraging. He noted that aspirin, anti-inflammatory drugs and statins have been studied for years for their role in colorectal cancer prevention, and this study adds GLP-1 receptor agonists to that conversation.

“These findings show that GLP-1 receptor agonists may have benefits far beyond the waistline,” Dr. Saltzman said, adding that further research is essential to fully understand how these drugs might be integrated into future cancer prevention strategies.

Researchers plan to validate the findings through clinical trials. Until then, experts stress that results presented at medical conferences should be viewed as preliminary and not a substitute for established screening and prevention measures.