Glucagon-like peptide-1 receptor (GLP-1R) is a member of the G protein-coupled receptor (GPCR) family, primarily expressed in pancreatic β-cells, the heart, gastrointestinal tract, and central nervous system. GLP-1R activates the cAMP signaling pathway, promoting insulin secretion, inhibiting glucagon release, and slowing gastric emptying, thereby lowering blood sugar levels. Additionally, GLP-1R plays a role in appetite regulation and cardiovascular protection. Gene variations and specific expression patterns are associated with the risk of type 2 diabetes, obesity, and cardiovascular diseases. Agonists targeting GLP-1R have become important drugs for treating type 2 diabetes and obesity.