Incretin Analogues for Weight Reduction in Non-Diabetic Obese: A Review of Liraglutide, Semaglutide, and Tirzepatide Beyond Glycemic Control.

This narrative review examines three incretin-based therapies — liraglutide, semaglutide, and tirzepatide — approved for weight management in non-diabetic individuals with obesity. The authors provide background on the physiological roles of the incretin hormones GIP and GLP-1 in the gastrointestinal tract, explaining how pharmacological analogues of these hormones, initially developed for type 2 diabetes, were subsequently found to produce clinically meaningful weight reduction. The review compares the three agents across efficacy, safety, cost-effectiveness, and real-world clinical trends. Lifestyle interventions (dietary modification, physical activity, sleep, and stress management) are discussed as foundational components of obesity management. The authors highlight that all three agents are now regulatory-approved for obesity in non-diabetic patients. As a narrative review, the paper synthesizes existing literature rather than generating new primary data, and is therefore subject to selection bias in the studies chosen. It does not conduct a formal systematic search or meta-analysis, limiting the objectivity of comparisons. No new clinical trial data are presented, and conclusions about relative efficacy and cost-effectiveness are drawn from the authors' interpretation of the existing evidence base.

Why this grade: This is a narrative review synthesizing existing literature on incretin analogues for obesity; it generates no new primary clinical or experimental data and is therefore graded as review-level evidence.