Dear sir i can understand your concern usually in diabetes as duration of diabetes increases there will be increased in loss of insulin producing cells called beta cells. so usually after few years of usage metformin may not support your diabetes it dosent mean to stop metformin. Since metformin is a very good drug please continue metformin and add other drugs like DPP 4 inhibitors check your sugar levels twice a week before breakfast and 2 hrs after break fast before lunch and 2 hrs after lunch,,,,not daily but twice a week. I suppose I have given the desired response if you have any other query please write back. Otherwise please accept & rate my answer. I will appreciate your review about my answer. Best Regards. Dr Vamsi Krishna Consultant Diabetologist