There are nine classes of antidiabetic drugs for people with type 2 diabetes, including insulin, metformin, sulfonylureas, glucagon-like peptide-1 agonists (GLP-1 RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i), dipeptidyl peptidase-4 inhibitors (DPP-4i), thiazolidinediones, acarbose, and meglitinides. Here, GLP1R is linked to type 2 diabetes mellitus.