Sitagliptin metformin tablet is useful in treating Type 2 Diabetes Mellitus and used in addition to diet and exercise that improves the blood sugar control with type 2 diabetes. It also help pancreas ffective use of insulin by the body, and reduces excess sugar that your liver makes. Metformin is a biguanide which lowers down the glucose production in the liver and delays glucose absorption from intestines and increases the bodys sensitivity to insulin. Hence they provider better control of blood sugar.