19.7% Average Loss With Tirzepatide at 176 Weeks
SURMOUNT-1 extension results: tirzepatide 15 mg produced 19.7% average weight loss at 176 weeks in adults with obesity and prediabetes, with study limits.
At week 176, mean body-weight change was −12.3% with tirzepatide 5 mg, −18.7% with 10 mg, and −19.7% with 15 mg, versus −1.3% with placebo.
1,032 adults with obesity and prediabetes from the 2,539-person SURMOUNT-1 parent trial; 176-week treatment period; 193 weeks including the off-treatment follow-up. Read the linked peer-reviewed source for the full methodology, findings, and limitations.
Jastreboff et al., NEJM 2025 · SURMOUNT-1 three-year extension