Even though sustained stimulation of the GLP-1 receptor is known to be associated with tachyphylaxis for the slowing of gastric emptying by GLP-1 [46], there is recent evidence that exenatide QW [47] and semaglutide [48] may retain some capacity to slow gastric emptying in health and T2D with prolonged use. This evidence concerns the gene GCG and type 2 diabetes mellitus.