However, while metformin can directly elicit a mild gastrointestinal intolerance, the correlation with insulin therapy may underline a long-standing T2D with poor glycemic control, a condition commonly associated with impaired gastric motility, which may accentuate the deceleration of gastric emptying induced by exogenous GLP1 RAs [67]. This evidence concerns the gene GLP1R and type 2 diabetes mellitus.