Tirzepatide (MounjaroTM) is a novel synthetic dual agonist of the GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) receptors, often referred to as a “twincretin.” It has been recently approved for the treatment of type 2 diabetes and has demonstrated significant efficacy in improving glycemic control while inducing substantial weight loss in clinical trials. This evidence concerns the gene GLP1R and type 2 diabetes mellitus.