Januvia (sitagliptin) is an effective oral medication option for treating Type 2 diabetes in adults. On average, Januvia lowers hemoglobin A1C (average blood glucose levels over 3 months) by up to 0.8%. It also has a low risk of hypoglycemia (low blood glucose) and doesn't cause weight gain. You may be prescribed Januvia on its own, but it's often used in combination with other diabetes medications. View original source