The overview below is meant to give you a full picture of Januvia, how it works, and important precautions and side effects that you should be aware of before starting the treatment. Describe Januvia. Januvia is a drug that can only be bought with a doctor's prescription and is used to treat the symptoms of Type 2 Diabetes Mellitus. Januvia can be taken alone or along with other medicines. Januvia comes from a class of drugs called Antidiabetics, Dipeptyl Peptidase-IV Inhibitors. Januvia pills contain sitagliptin phosphate, which is an inhibitor of the dipeptidyl peptidase4 (DPP-4) enzyme that works when taken by mouth. Januvia is often used in addition to diet and exercise to help people with type 2 diabetes mellitus better control their blood sugar. How does Januvia do its job? Januvia, which is also called Sitagliptin, is taken along with a healthy diet and exercise, as well as other medicines, to control high blood sugar. Controlling high blood sugar can help keep people from going blind, hurting their kidneys, having nerve problems, losing limbs, and having sexual problems. If you keep your diabetes under control, you may also be less likely to have a stroke or heart attack. Januvia is a drug used to treat diabetes. It works by increasing the levels of natural substances called incretins. Januvia helps control blood sugar by making insulin come out more quickly, mostly after eating. They also tend to cut down on how much sugar the liver makes. Side Effects of Januvia Even though low blood sugar (hypoglycemia) usually doesn't happen when Januvia is taken on its own, it can happen when Januvia is taken with other diabetes drugs. If you notice signs of low blood sugar, talk to your doctor or pharmacist about the possibility of lowering the dose of your diabetes medicine.