Three-year SURMOUNT-1 data: tirzepatide cut the risk of developing type 2 diabetes by 94% in adults with pre-diabetes

Eli Lilly/Tirzepatide (Mounjaro / Zepbound)

In the three-year SURMOUNT-1 extension, tirzepatide cut progression to type 2 diabetes by 94% versus placebo in 1,032 pre-diabetic adults with obesity or overweight. Weight fell 22.9% on the 15 mg dose versus 2.1% on placebo; after stopping, weight began returning but diabetes risk remained 88% lower over 17 weeks.

• 176-week trial (3 years); tirzepatide maintained weight loss and diabetes prevention throughout treatment.
• After stopping, patients regained some weight but diabetes risk stayed substantially lower, suggesting durable metabolic benefit.
• 22.9% weight loss on the highest dose is among the largest reported for an obesity drug.
• Results support tirzepatide's dual GIP/GLP-1 mechanism for both glucose control and weight reduction.