Evolution of incretin-based therapies: From GLP-1 monotherapy to dual and triple agonists: A new era in metabolic therapy.
This narrative review synthesizes the evolution of incretin-based pharmacotherapies for metabolic disorders, drawing on literature from PubMed, Scopus, and Google Scholar up to July 2025. The authors trace the trajectory from DPP-4 inhibitors—noted for modest glycaemic benefits—through GLP-1 receptor agonists (GLP-1RAs) such as liraglutide and semaglutide, which pivotal trials have associated with meaningful weight loss and cardiometabolic protection, to next-generation agents. Dual GIP/GLP-1 agonist tirzepatide and triple agonist retatrutide are highlighted as demonstrating particularly substantial efficacy, with the review citing up to 24% body weight reduction alongside improvements in hepatic and inflammatory markers in included trials. Agents such as cotadutide and efinopegdutide are discussed in the context of expanding indications to MASLD and MASH. The authors acknowledge several limitations across the field: high cost and accessibility barriers, underrepresentation of low- and middle-income country populations in major trials, and pharmacogenomic variability that may modify therapeutic response. As a review, this paper does not generate new primary data. Its conclusions depend on the quality and representativeness of the underlying trials it synthesizes, and no independent meta-analytic pooling appears to have been conducted.
Why this grade: This is a narrative review synthesizing existing literature rather than generating primary human or experimental data, so it is graded as "review" rather than a direct evidence tier.
Incretin-based therapies have revolutionised the management of metabolic disorders, transitioning from DPP-4 inhibitors to advanced GLP-1 receptor agonists (GLP-1RAs) and next-generation dual and triple agonists. This review explores the evolving role of incretin pharmacology in type 2 diabetes mellitus (T2DM), obesity, and metabolic dysfunction-associated steatotic liver disease (MASLD). Literature from PubMed, Scopus, and Google Scholar up to July 2025 was reviewed, emphasising pivotal trials and real-world evidence. While DPP-4 inhibitors offer modest glycaemic benefits, GLP1RAs such as liraglutide and semaglutide have demonstrated significant weight loss and cardiometabolic protection. Dual GIP/GLP-1 agonist tirzepatide and triple agonist retatrutide have shown unprecedented efficacy, with up to 24% body weight reduction and improvement in hepatic and inflammatory markers. Agents like cotadutide and efinopegdutide further expand indications to MASLD and metabolic dysfunction associated steatohepatitis (MASH). Despite promising outcomes, challenges persist in terms of cost, accessibility, and the underrepresentation of low- and middle-income countries in major trials. Pharmacogenomic variability may also influence therapeutic response. Incretin-based multi-agonists offer a transformative, multi-system approach to metabolic disease but require tailored implementation. This review provides an updated synthesis of therapeutic developments and outlines priorities for future research, regulatory policy, and equitable global integration as incretin-based therapies have evolved into a versatile class addressing glycaemic control, weight loss, and cardio-metabolic risk.
Educational summary of published research — not medical advice. License: cc by-nc-sa. Full text is shown only where licensing permits.