JANUVIA is a once-daily pill that, along with diet and exercise, helps lower blood sugar levels in adults with type 2 diabetes. JANUVIA is a type of prescription medicine called a DPP-4 inhibitor (blocker). DPP-4 blockers enhance the body's own ability to control blood sugar levels.
JANUVIA helps your body:

JANUVIA works only when your blood sugar levels are high
Because JANUVIA stops working before your blood sugar gets too low, it is not likely to lower your blood sugar to a potentially dangerous level (hypoglycemia). When your blood sugar levels are at a healthy balance, JANUVIA doesn't have an effect. When JANUVIA is used with a sulfonylurea, low blood sugar (hypoglycemia) can occur. To avoid this risk, your doctor may prescribe lower doses of the sulfonylurea.
Most people who took JANUVIA did not gain weight
Keeping at a healthy weight is an important part of taking care of your diabetes. A healthy weight is good for your heart and can help keep your blood sugar levels balanced. Most people with type 2 diabetes struggle to reach or maintain a healthy weight. This can be discouraging. So you’ll be glad to know that most patients who took JANUVIA did not gain weight.
A doctor may prescribe JANUVIA alone or together with certain other diabetes medicines to help control blood sugar. Take JANUVIA exactly as your doctor has prescribed and follow your doctor’s treatment plan for healthy eating and exercise.
Learn more about taking JANUVIA.