GLP-1 receptor agonist injections, commonly known by brand names like Ozempic and Mounjaro, may be more effective than metformin in preventing type 2 diabetes, according to a large analysis.
The study found that individuals taking these "fat jabs" had a 31% lower risk of developing type 2 diabetes compared to those on metformin, the standard treatment for the condition. Furthermore, patients on the injections experienced a 41% lower risk of all-cause mortality and showed reduced instances of heart attack, stroke, and heart failure.
Researchers suggest these findings could support the use of GLP-1 medications for prevention, especially in patients with prediabetes. Prediabetes affects approximately one in 12 people in the UK and is characterized by blood sugar levels that are elevated but not yet high enough for a type 2 diabetes diagnosis.
The analysis examined the medical records of over 250,000 adults diagnosed with obesity and prediabetes. Half of these participants were using drugs such as semaglutide (found in Ozempic and Wegovy) or tirzepatide (found in Mounjaro). The other half were taking metformin, which is prescribed to roughly three million of the 4.2 million people diagnosed with type 2 diabetes in Britain, and sometimes used off-label for prevention.
The research indicated that patients on GLP-1 injections were 50% more likely to achieve normal blood sugar levels, significantly lowering their risk of progressing to type 2 diabetes. Additional benefits included a 25% reduction in heart failure cases, 20% fewer strokes, and 15% fewer heart attacks. Cases of atrial fibrillation, a heart rhythm disorder that can lead to stroke, were also 8% lower.
Experts theorize that the significant weight loss associated with these injections contributes to improved insulin sensitivity and healthier blood sugar levels. However, the study's author, Dr. Vinicius de Sousa Barzon Serra, emphasized that metformin remains a crucial first-line treatment due to its lower cost, with the injections potentially costing up to £300 per month. He suggested the findings highlight additional options for specific patients rather than a direct replacement for metformin.
Robert Eckel, former volunteer president of the American Heart Association, commented that these weight loss injections "provide another option for prevention." The research is slated for presentation at the American Heart Association’s Scientific Sessions 2026, but it has not yet undergone peer review or been published in a scientific journal. The study's authors cautioned that, as it is based on medical records and not a clinical trial, it cannot definitively prove that the drugs directly caused the observed benefits.