Comparative effects of proximal and distal small intestinal administration of metformin on plasma glucose and glucagon-like peptide-1, and gastric emptying after oral glucose, in type 2 diabetes.

In diet-controlled T2DM patients, glucose-lowering via a single dose of metformin administered to the upper and lower gut was comparable and was associated with stimulation of GLP-1 and slowing of GE. These observations suggest that the site of gastrointestinal administration is not critical to the glucose-lowering capacity of metformin.