Preoperative GLP-1 agonists yield moderate weight loss before bariatric surgery, meta-analysis findsGLP-1 drugs before weight loss surgery: modest benefit, no extra risk

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.