SN instructed about the use of Januvia ( Sitagliptin ) is used along with diet and exercise and sometimes with other medications to lower blood sugar levels in patients with type 2 diabetes. It works by increasing the amounts of certain natural substances that lower blood sugar when it is high. Over time, people who have diabetes and high blood sugar can develop serious or life - threatening complications, including heart disease, stroke, kidney problems, nerve damage, and eye problems. Taking medication,making lifestyle changes, and regularly checking your blood sugar may help to manage your diabetes and improve your health. This therapy may also decrease your chances of having a heart attack, stroke, or other diabetes - related complications such as kidney failure, nerve damage, eye problems, including changes or loss of vision, or gum disease.