Incretin-Based Interventions for Diabetes and Obesity: An Evaluation of GIP/GLP-1 Dual Agonism Versus Selective GLP-1 Receptor Agonism

Diabetes mellitus and obesity remain preeminent global health crises, with diabetes prevalence exceeding 589 million and obesity projected to affect half of the global adult population by 2030. The advent of incretin-based pharmacotherapy has revolutionized the management of these metabolic conditions. This review synthesizes two converging domains: the superior clinical profile of dual glucose-dependent insulinotropic polypeptide (GIP)/glucagon-like peptide-1 (GLP-1) receptor agonism compared to selective GLP-1 agonism, and the cellular determinants of GIP-mediated metabolic improvements. Drawing on pivotal data from the SURMOUNT-5 head-to-head trial, the SURPASS clinical program, and the Ravussin metabolic sub-study, we observe that dual agonism provides a significant clinical advantage; tirzepatide achieved 20.2% mean weight loss compared with 13.7% for semaglutide at 72 weeks. Mechanistically, GIP receptor activation facilitates weight loss through enhanced fat oxidation, optimized adipose tissue lipid buffering, and adiponectin-mediated insulin sensitization, alongside complementary central nervous system (CNS)-mediated appetite suppression. Despite challenges, including the “GIP paradox” (agonism vs. antagonism), reliance on rodent models, and a lack of long-term longitudinal data, the evidence establishes dual incretin agonism as a therapeutic leap. Future perspectives highlight triple receptor agonists and pharmacogenomic stratification as the next frontiers in precision metabolic medicine.