GCG and type 2 diabetes mellitus: The impact on postprandial glucose-lowering of altering the timing of metformin administration in relation to meals has been poorly characterised, although an open-label pilot study in five metformin-treated type 2 diabetes patients was indicative of improved glucose-lowering, enhanced GLP-1 secretion and slowed gastric emptying when metformin (1000 mg) was administered 30 min before the meal rather than with the meal [24].