How Does Tirzepatide Compare to Other GLP-1 Drugs When Added to Insulin?

Tirzepatide at all doses produced significantly greater reductions in HbA1c and body weight than GLP-1 receptor agonists when used with basal insulin.

Osumili, Beatrice et al.·Diabetes therapy : research·2025·Strong EvidenceMeta-Analysis
RPEP-12889Meta AnalysisStrong Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Meta-Analysis
Evidence
Strong Evidence
Sample
Adults with type 2 diabetes on basal insulin, drawn from 6 randomized controlled trials comparing tirzepatide to GLP-1 receptor agonists.
Participants
Adults with type 2 diabetes on basal insulin, drawn from 6 randomized controlled trials comparing tirzepatide to GLP-1 receptor agonists.

What This Study Found

Tirzepatide at all doses (5, 10, 15 mg) significantly outperformed GLP-1 RAs for both blood sugar control and weight loss when combined with basal insulin.

Key Numbers

  • 6 randomized controlled trials included in the network meta-analysis
  • Tirzepatide at all 3 doses (5, 10, 15 mg) showed significantly greater HbA1c reduction vs all GLP-1 comparators
  • Tirzepatide at all 3 doses showed significantly greater weight reduction vs all GLP-1 comparators
  • No significant differences in treatment discontinuation rates vs GLP-1 comparators (except tirzepatide 10/15 mg vs placebo)

How They Did This

Network meta-analysis of 6 randomized controlled trials comparing tirzepatide with GLP-1 RAs in patients on basal insulin.

Why This Research Matters

Many type 2 diabetes patients need add-on therapy to insulin. This analysis suggests tirzepatide may offer superior benefits over existing GLP-1 drugs in this population.

The Bigger Picture

As dual GIP/GLP-1 receptor agonists like tirzepatide emerge, they may become preferred add-on therapies for insulin-treated patients needing better glycemic and weight control.

What This Study Doesn't Tell Us

Indirect comparison via network meta-analysis, not head-to-head trials. Limited number of studies (6). Relatively short follow-up at primary endpoints.

Questions This Raises

  • ?Would tirzepatide maintain superiority in longer-term studies?
  • ?How does tirzepatide compare to semaglutide specifically in this population?

Trust & Context

Key Stat:
All 3 doses superior Tirzepatide 5, 10, and 15 mg all showed statistically significant greater HbA1c and weight reductions vs. all GLP-1 RA comparators
Evidence Grade:
Network meta-analysis of RCTs provides moderate-to-high quality evidence, though indirect comparisons carry more uncertainty than head-to-head trials.
Study Age:
Published in 2025 based on existing RCT data.
Original Title:
Efficacy and Safety of Tirzepatide Compared with GLP-1 RAs in Patients with Type 2 Diabetes Treated with Basal Insulin: A Network Meta-analysis.
Published In:
Diabetes therapy : research, treatment and education of diabetes and related disorders, 16(6), 1279-1311 (2025)
Database ID:
RPEP-12889

Evidence Hierarchy

Meta-Analysis / Systematic ReviewCombines many studies into one answer
This study
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Combines results from multiple studies to find an overall pattern.

What do these levels mean? →

Frequently Asked Questions

Is tirzepatide better than GLP-1 drugs for people on insulin?

This analysis found tirzepatide at all tested doses produced greater reductions in blood sugar and body weight compared to dulaglutide, exenatide, and lixisenatide when added to basal insulin.

Does tirzepatide cause more side effects?

Tirzepatide caused more nausea than placebo and exenatide, but side effect rates were similar to other GLP-1 drugs overall.

Read More on RethinkPeptides

Cite This Study

RPEP-12889·https://rethinkpeptides.com/research/RPEP-12889

APA

Osumili, Beatrice; Sapin, Hélène; Yang, Zhengyu; Ranta, Kari; Paik, Jim S; Blüher, Matthias. (2025). Efficacy and Safety of Tirzepatide Compared with GLP-1 RAs in Patients with Type 2 Diabetes Treated with Basal Insulin: A Network Meta-analysis.. Diabetes therapy : research, treatment and education of diabetes and related disorders, 16(6), 1279-1311. https://doi.org/10.1007/s13300-025-01728-5

MLA

Osumili, Beatrice, et al. "Efficacy and Safety of Tirzepatide Compared with GLP-1 RAs in Patients with Type 2 Diabetes Treated with Basal Insulin: A Network Meta-analysis.." Diabetes therapy : research, 2025. https://doi.org/10.1007/s13300-025-01728-5

RethinkPeptides

RethinkPeptides Research Database. "Efficacy and Safety of Tirzepatide Compared with GLP-1 RAs i..." RPEP-12889. Retrieved from https://rethinkpeptides.com/research/osumili-2025-efficacy-and-safety-of

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.