Januvia (sitagliptin) is a medication classified as a dipeptidyl peptidase-4 (DPP-4) inhibitor. It works by increasing the levels of incretin hormones in the body, which helps to lower blood sugar levels in patients with type 2 diabetes. Januvia is indicated for the treatment of type 2 diabetes mellitus. It is used in conjunction with diet and exercise to improve glycemic control in adults with diabetes. Clinical studies have shown that Januvia effectively reduces hemoglobin A1c levels, which reflects the average blood sugar levels over time. By inhibiting DPP-4, Januvia prolongs the action of incretin hormones, stimulating the release of insulin and decreasing the production of glucagon. This leads to a decrease in blood sugar levels after meals and helps manage diabetes.