It is an oral prescription medicine that, along with diet and exercise, helps lower blood sugar in adults with type 2 diabetes. these tablets contain 2 prescription medicines: sitagliptin and metformin. your doctor will determine whether it is right for you.it targets 3 key factors to lower blood sugar: helps your pancreas make more insulin helps your body more effectively use the insulin that it makes helps decrease excess sugar that your liver makes helps control blood sugar throughout the day, including after meals is not likely to cause weight gain and low blood sugar (hypoglycemia) by itselfit can lower blood sugar more than metformin alone.it is a powerful type 2 diabetes medicine that combines 2 prescription medicines, sitagliptin and metformin, and can lower blood sugar more than the most commonly prescribed medicine (metformin).