Multiple classes of medications are approved for treating T2D: biguanides (e.g., metformin), sulfonylureas, thiazolidinediones, dipeptidyl peptidase 4 inhibitors, SGLT-2 inhibitors (empagliflozin, ertugliflozin, dapagliflozin, canagliflozin), GLP-1 analogs (semaglutide, liraglutide), dual GLP-1 receptor agonist and GIP analog (tirzepatide), retatrutide (a triple agonist of GIP, GLP-1, and glucagon receptors), insulins, α-glucosidase inhibitors, dopaminergic antagonists, bile acid sequestrants, meglitinides, and amylin analogs [24,26,27,28,29,30]. This evidence concerns the gene GCG and type 2 diabetes mellitus.