Evidence
What the trials actually showed.
How it works
Tirzepatide is a dual GLP-1 / GIP receptor agonist. Four practical effects:
GLP-1 activity
Glucose-dependent insulin release; lowers post-meal glucose.
GIP activity
Improves insulin sensitivity and lipid handling.
Slower gastric emptying
Longer satiety, smaller portions, fewer cravings.
Central appetite signaling
Reduced food-seeking and reward-driven eating.
SURPASS
SURPASS — type 2 diabetes
Phase 3, head-to-head against placebo, semaglutide, insulin degludec, and insulin glargine.
| Trial | N | Duration | HbA1c change |
|---|---|---|---|
| SURPASS-1 | 478 | 40 wk | −2.07% |
| SURPASS-2 | 1,879 | 40 wk | −2.30% |
| SURPASS-3 | 1,444 | 52 wk | −2.37% |
| SURPASS-5 | 475 | 40 wk | −2.59% |
Mean placebo-adjusted change at the highest dose tested. Individual response varies.
SURMOUNT
SURMOUNT — weight management
Phase 3, in adults with obesity or overweight + at least one weight-related condition.
| Trial | N | Duration | Weight change |
|---|---|---|---|
| SURMOUNT-1 | 2,539 | 72 wk | −22.5% |
| SURMOUNT-2 | 938 | 72 wk | −15.7% |
| SURMOUNT-3 | 806 | 88 wk | −18.4% |
| SURMOUNT-4 | 783 | 88 wk | −25.3% |
Mean weight change at 15 mg, baseline BMI ≥ 30 kg/m² (or ≥ 27 with a comorbidity).