Gastrointestinal tolerability and weight reduction associated with tirzepatide in adults with obesity or overweight with and without type 2 diabetes in the SURMOUNT-1 to -4 trials.

Rubino, Domenica M et al.·Diabetes·2025·Strong Evidencepost hoc analysis of randomized controlled trials
RPEP-13323Post hoc analysis of randomized controlled trialsStrong Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
post hoc analysis of randomized controlled trials
Evidence
Strong Evidence
Sample
N=Pooled from SURMOUNT-1 to -4 (thousands of participants)
Participants
Adults with obesity or overweight, with or without type 2 diabetes

What This Study Found

GI side effects like nausea and vomiting contributed at most 3.1% of the total weight loss seen with tirzepatide across the SURMOUNT trials.

Key Numbers

GI AEs in 27.8-72.8% of tirzepatide vs 12.2-32.5% of placebo; 1.0-10.5% discontinued due to GI AEs; GI mediated up to 3.1% of weight loss

How They Did This

Post hoc analysis pooling data from SURMOUNT-1 through -4 Phase 3 trials. Compared weight change by GI symptom status. Mediation analysis quantified GI contribution to weight loss.

Why This Research Matters

Some critics suggested GLP-1 drugs only work because they make people feel sick. This analysis shows tirzepatide produces nearly the same weight loss whether or not patients have GI symptoms.

What This Study Doesn't Tell Us

Post hoc analysis, not prespecified. GI symptoms were self-reported. Mediation analysis assumes causal pathways that may not fully hold. Pooling across trials with different populations.

Trust & Context

Original Title:
Gastrointestinal tolerability and weight reduction associated with tirzepatide in adults with obesity or overweight with and without type 2 diabetes in the SURMOUNT-1 to -4 trials.
Published In:
Diabetes, obesity & metabolism, 27(4), 1826-1835 (2025)
Database ID:
RPEP-13323

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

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Cite This Study

RPEP-13323·https://rethinkpeptides.com/research/RPEP-13323

APA

Rubino, Domenica M; Pedersen, Sue D; Connery, Lisa; Cao, Dachuang; Chigutsa, Farai; Stefanski, Adam; Fraseur Brumm, Julia; Griffin, Ryan; Gerber, Claire. (2025). Gastrointestinal tolerability and weight reduction associated with tirzepatide in adults with obesity or overweight with and without type 2 diabetes in the SURMOUNT-1 to -4 trials.. Diabetes, obesity & metabolism, 27(4), 1826-1835. https://doi.org/10.1111/dom.16176

MLA

Rubino, Domenica M, et al. "Gastrointestinal tolerability and weight reduction associated with tirzepatide in adults with obesity or overweight with and without type 2 diabetes in the SURMOUNT-1 to -4 trials.." Diabetes, 2025. https://doi.org/10.1111/dom.16176

RethinkPeptides

RethinkPeptides Research Database. "Gastrointestinal tolerability and weight reduction associate..." RPEP-13323. Retrieved from https://rethinkpeptides.com/research/rubino-2025-gastrointestinal-tolerability-and-weight

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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.