We cannot advise what is best for you. That is beween you and your HCP team to decide, But one aspect of the way Metformin works springs to mind, and that is it acts to inhibit the digestion of carbs and so reduce the amount of glucose getting to the liver. In this respect the dose in the morning might be improved if it became the larger dose since it needs to act on food which may not happen last thing at night. Other than that I think Metformin is a slow drug that needs to build up over time, so altering the timing is not so critical as say insulin. The other thing reported is that many here benefit from taking Metformin with food to reduce stomach upset, and again the larger dose should accompany food as per the user leaflet.