Tirzepatide Research

Jastreboff AM, Aronne LJ, Ahmad NN, et al. — SURMOUNT-1 Investigators

The pivotal trial establishing tirzepatide for obesity treatment. In 2,539 adults with obesity (without diabetes) over 72 weeks, tirzepatide produced average weight losses of 15.0% (5mg), 19.5% (10mg), and 20.9% (15mg) — compared to 3.1% with placebo. At the highest dose, 57% of participants lost 20% or more of their body weight — a level of weight loss previously achievable only through bariatric surgery. This was the first trial demonstrating the dual GIP/GLP-1 mechanism’s superior weight loss over single GLP-1 agonists.

Jastreboff AM, le Roux CW, Stefanski A, et al. — SURMOUNT-1 Investigators

Three-year follow-up of SURMOUNT-1 participants with prediabetes. Tirzepatide maintained 19.7% weight loss at 176 weeks and dramatically reduced diabetes progression — only 1.3% of tirzepatide participants developed type 2 diabetes compared to 13.3% of those on placebo, representing a 93% relative risk reduction. Even 17 weeks after stopping treatment, the protection against diabetes development persisted — suggesting the weight loss itself is driving lasting metabolic benefit.

Aronne LJ, Bade Horn D, le Roux CW, et al. — SURMOUNT-5 Investigators

The first direct head-to-head comparison of tirzepatide and semaglutide for obesity. In 751 adults with obesity over 72 weeks, tirzepatide produced 20.2% average weight loss compared to 13.7% with semaglutide — a clinically meaningful difference of 6.5 percentage points favoring tirzepatide. Waist circumference reductions were also significantly greater with tirzepatide. This trial established tirzepatide as the more potent weight loss agent when the two are compared directly at maximum tolerated doses.

Bhatt DL, Raman SV, et al.

The SUMMIT trial enrolled 731 adults with obesity-related heart failure with preserved ejection fraction (HFpEF) — a condition with very limited treatment options. Tirzepatide significantly improved exercise capacity, reduced symptoms, and led to greater weight loss compared to placebo. This extended tirzepatide’s clinical evidence base to heart failure, one of obesity’s most serious cardiovascular complications.