Preoperative GLP-1 agonists yield moderate weight loss before bariatric surgery, meta-analysis finds

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Surgery for obesity and related diseases : official journal of the American Society for Bariatric Surgery Published June 1, 2026 Medically reviewed June 1, 2026 Study authors: Liu Chenming, Tian Peirong, Li Mengyi, Liu Yang, Liu Jingli, Zhang Zhongtao, Zhang Peng PubMed ↗ DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Consider preoperative GLP-1 RAs for modest weight loss before bariatric surgery, but note no clear postoperative benefit.

This systematic review and meta-analysis evaluated the effect of preoperative glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in patients with obesity undergoing metabolic and bariatric surgery. The analysis included 5461 patients from studies conducted worldwide. The primary outcomes were preoperative weight change and postoperative total weight loss percentage (TWL%).

Preoperative administration of GLP-1 RAs was associated with a moderate reduction in weight before surgery (SMD 0.4; 95% CI -.37 to 1.18, P < .01), corresponding to a median weight reduction of 4.87 kg versus 3.84 kg in the comparator group. However, no significant effect was observed on postoperative TWL% (SMD -.20; 95% CI -.27 to -.13, P = .21). The incidence of postoperative complications did not significantly increase (RR 1.62; 95% CI .76-3.45, P = .12), and there was no significant improvement in comorbidities (P = .23).

The authors did not report specific limitations, but the analysis likely includes observational studies, so causality cannot be inferred. The certainty of evidence was not reported. The findings suggest a potential role for preoperative GLP-1 RAs in facilitating weight loss before surgery, but the lack of benefit on postoperative outcomes and the modest effect size warrant cautious interpretation. Clinicians should weigh individual patient factors when considering this approach.

Study Details

Study typeMeta analysis

EvidenceLevel 1

PublishedJun 2026

PMID41887957

View Original Abstract ↓

BACKGROUND: The perioperative effect of preoperative administration of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in individuals with obesity scheduled to receive metabolic and bariatric surgery (MBS) remains uncertain. OBJECTIVES: The objective of this systematic review and meta-analysis was to evaluate the efficacy of preoperative GLP-1 RAs in patients with obesity undergoing MBS. SETTING: All over the world. METHODS: Original studies were searched from the inception of PubMed, Embase, and Web of Science up to September 2025. Primary outcomes were the variation of weight from the initial to the preoperative period and postoperative total weight loss percentage (TWL%). Secondary outcomes included the incidence of postoperative complications, postoperative glycated hemoglobin level, and the proportion of patients with remission of diabetes. RESULTS: After screening, 10 studies consisting of 5461 subjects were included in the final meta-analysis. The results showed that preoperative GLP-1 RAs were associated with a moderate reduction in preoperative weight (total median of weight reduction: 4.87 kg vs 3.84 kg; SMD: .4, 95% CI: -.37 to 1.18, P < .01) but did not significantly affect postoperative TWL% (SMD: -.20, 95% CI: -.27 to -.13, P = .21). Preoperative administration of GLP-1 RAs did not significantly increase the incidence of postoperative complications (RR: 1.62, 95% CI: .76-3.45, P = .12) nor improve the comorbidities (P = .23). CONCLUSIONS: Our study indicates that preoperative GLP-1 RAs are generally safe for patients with obesity undergoing MBS. However, this benefit only correlates with a certain degree of preoperative weight loss, and its effect on postoperative weight loss and improvement of comorbidities are limited.