Tirzepatide was compared to semaglutide for treatment of type 2 diabetes in patients taking metformin in a 40-week randomized controlled trial. Tirzepatide at doses of 5mg, 10mg and 15mg resulted in greater reductions in HbA1c and body weight compared to semaglutide 1mg. Common side effects were mild to moderate gastrointestinal issues. Tirzepatide demonstrated superior glycemic control and weight loss over semaglutide and may allow more patients to achieve strict treatment targets while maintaining a low risk of hypoglycemia.