Oral GLP-1-Based Therapeutics in the Obesity–Metabolic Syndrome–Diabetes Continuum: Translational Advances, Clinical Barriers, and Emerging Strategies

The obesity–metabolic syndrome–diabetes continuum is driven by interconnected mechanisms including insulin resistance, dysfunctional adiposity, chronic inflammation and progressive cardio–renal–metabolic injury. This triggered a need for therapies that extend beyond glucose lowering alone. The benefits of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) as disease-modifying drugs include weight loss, cardiovascular risk reduction, glycemic control and renal protection. However, treatment burden, adherence issues and access restrictions may limit the long-term effects of injectable formulations. One significant translational development that aims to close this gap is oral GLP-1-based treatments. In this review, we examine the mechanistic rationale, formulation science and clinical development of oral GLP-1 RAs. Oral semaglutide is presented as the first validated proof of concept for systemic peptide delivery by the gastrointestinal route. The biological barriers to oral peptide absorption, including enzymatic degradation, low epithelial permeability, pharmacokinetic variability and epithelial safety constraints, are critically discussed. Enabling technologies such as SNAC-based gastric absorption, nanocarriers, mucoadhesive systems and stability-optimization platforms are evaluated. Evidence from the PIONEER program and related studies demonstrating meaningful glycemic and weight-loss efficacy, acceptable safety and clinical utility in patients with type 2 diabetes and chronic kidney disease is further synthesized. Beyond first-generation oral peptide platforms, we discuss the emerging landscape of non-peptide oral GLP-1 RAs, dual and triple incretin agonists, precision dosing strategies and model-informed drug development. Oral GLP-1-based therapeutics are shifting from a formulation breakthrough to a broader translational strategy for disease modification across the obesity–metabolic syndrome–diabetes continuum. Long-term renal outcomes, access and implementation barriers remain important priorities for future research.