Incretin-Based Multi-Agonist Therapies for Type 2 Diabetes Mellitus and Obesity: Mechanisms, Clinical Efficacy, and Future Directions

Type 2 diabetes mellitus (T2DM) and obesity affect hundreds of millions of adults worldwide and represent leading drivers of cardiovascular disease, chronic kidney disease, and escalating healthcare expenditures. Incretin-based therapies have fundamentally reshaped cardiometabolic disease management, with dual- and triple-receptor agonists extending the benefits of traditional glucagon-like peptide-1 (GLP-1) receptor agonism. By synthesizing clinical, mechanistic, and real-world data, this review examines the evolving therapeutic landscape of GLP-1-based multi-agonists. Dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) receptor agonists demonstrate superior metabolic efficacy compared with GLP-1 receptor agonists alone, achieving greater reductions in body weight and glycemic indices across diverse patient populations. Emerging triple agonists targeting GLP-1, GIP, and glucagon receptors further enhance metabolic outcomes, with weight loss approaching that observed following bariatric surgery in late-phase clinical trials. Mechanistically, multi-receptor co- agonism produces synergistic effects through complementary pathways, including appetite suppression, glucose-dependent insulin secretion, improved adipose tissue metabolism, increased energy expenditure, enhanced hepatic lipid oxidation, and reductions in hepatic steatosis. Beyond glycemic and weight endpoints, GLP-1-based therapies confer clinically meaningful cardiovascular and renal protection. Trials consistently demonstrate reductions in major adverse cardiovascular events across populations with and without T2DM, while kidney-specific trials show significant slowing of disease progression. However, gastrointestinal adverse events remain common and contribute to substantial treatment discontinuation, particularly in real-world settings. Despite their transformative efficacy, the population-level impact of these therapies is constrained by significant implementation barriers, including high drug costs, limited insurance coverage, restrictive utilization management policies, and pronounced racial and socioeconomic disparities in access. Emerging innovations including oral formulations, longer-acting injectables, and novel peptide combinations look to improve tolerability, adherence, and scalability, while therapeutic indications continue to expand to conditions such as metabolic dysfunction-associated steatohepatitis, chronic kidney disease, obstructive sleep apnea, and neurodegenerative disease. This review provides a comprehensive framework for understanding the clinical potential, mechanistic basis, and real-world challenges of GLP-1-based multi-agonists and outlines key priorities for optimizing implementation and maximizing their impact on global cardiometabolic health.