Obesity and its related metabolic comorbidities, including type 2 diabetes, metabolic dysfunction-associated steatotic liver disease, and cardiovascular disease, are increasingly recognized as heterogeneous and multisystemic disorders. Despite the significant benefits in glycemic control and weight loss exhibited by GLP-1 receptor agonists (GLP-1RAs), their limitations have initiated the development of engineered multi-agonist therapies targeting additional nutrient-stimulated hormonal (NUSH) pathways. Dual and triple peptide-based co-agonists combining glucagon-like peptide-1 (GLP-1) with glucose-dependent insulinotropic polypeptide (GIP), glucagon, amylin, or peptide YY have demonstrated superior metabolic efficacy in preclinical and clinical studies. Tirzepatide (GLP-1/GIP dual agonist), CagriSema (GLP-1/amylin dual agonist), and retatrutide (GLP-1/GIP/glucagon triple agonist) have achieved unprecedented levels of weight loss and glycemic improvement, with certain agents also demonstrating hepatic, cardiovascular, and inflammatory benefits. Non-peptidyl oral GLP-1RAs, such as orforglipron, offer novel formulation strategies to enhance treatment accessibility and adherence. Multi-agonist incretin-based therapies represent a paradigm shift in the management of obesity and metabolic diseases. These agents offer broad clinical utility beyond glucose lowering by mimicking the pleiotropic hormonal responses observed after bariatric surgery. These therapies are poised to emerge as key components of precision metabolic medicine. This review article explores the mechanistic basis, pharmacological characteristics, and clinical data supporting the use of engineered NUSH-based peptide therapies for obesity and its related metabolic disorders, with particular emphasis on recent progress in the development and clinical application of dual and triple agonists.
