Tirzepatide Versus GLP-1 Receptor Agonists for Type 2 Diabetes: A Network Meta-Analysis of Glycemic and Weight Outcomes
Background
Tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 receptor agonist, has demonstrated substantial glycemic and weight-lowering effects in the SURPASS trial program. However, its comparative efficacy against the full range of available GLP-1 receptor agonists has not been systematically evaluated using network meta-analytical methods. We conducted a comprehensive network meta-analysis to establish the relative positioning of tirzepatide among incretin-based therapies.
Methods
We systematically searched PubMed, Embase, and the Cochrane Library through August 2025 for randomized controlled trials of at least 26 weeks duration comparing tirzepatide, semaglutide (oral and subcutaneous), dulaglutide, liraglutide, or exenatide with placebo or active comparators in adults with type 2 diabetes. The primary outcomes were change in HbA1c and body weight from baseline. A Bayesian network meta-analysis was performed using random-effects models. Surface under the cumulative ranking curve (SUCRA) values were calculated to rank treatments.
Results
Forty-two trials comprising 35,891 participants were included. For HbA1c reduction, tirzepatide 15 mg ranked first (SUCRA 97.2%) with a mean reduction of 2.24% (95% CrI, 2.01-2.47), followed by tirzepatide 10 mg (SUCRA 89.1%, -1.93%), semaglutide 2.0 mg subcutaneous (SUCRA 78.4%, -1.78%), and semaglutide 1.0 mg (SUCRA 68.3%, -1.55%). For weight reduction, tirzepatide 15 mg again ranked first (SUCRA 98.5%) with a mean reduction of 11.2 kg (95% CrI, 9.8-12.6), compared with 6.2 kg for semaglutide 1.0 mg and 4.7 kg for dulaglutide 4.5 mg. The proportion of patients achieving HbA1c below 7% was highest with tirzepatide 15 mg (91%) versus semaglutide 1.0 mg (74%). Gastrointestinal adverse events occurred more frequently with tirzepatide 15 mg (nausea 24%, diarrhea 18%) compared with semaglutide 1.0 mg (nausea 20%, diarrhea 12%).
Conclusions
In this network meta-analysis, tirzepatide 15 mg provided the greatest reductions in both HbA1c and body weight among all available incretin-based therapies for type 2 diabetes, although with a somewhat higher burden of gastrointestinal side effects.
Tirzepatide at 15 mg demonstrates superior glycemic control and weight reduction compared with all available GLP-1 receptor agonists in adults with type 2 diabetes, though gastrointestinal adverse events are also more frequent.