Abstract Pancreatic β-cell differentiation and regenerative capacity differ markedly between developmental stages, with the neonatal pancreas exhibiting high plasticity that enables ongoing progenitor- and ductal-derived β-cell formation, whereas the adult pancreas demonstrates limited neogenic potential. Glucagon-like peptide-1 (GLP-1) promotes β-cell survival, proliferation, and differentiation; however, its developmental stage-specific effects on β-cell regeneration are not fully understood.