Januviaand Onglyza increase the amount of glucagon-like peptide-1 (GLP-1) in the body. Under normal circumstances, GLP-1 lasts only a few minutes in the blood before an enzyme called dipeptidyl peptidase 4, or DPP-4, breaks it down. Januvia and Onglyza prevent DPP-4 from breaking down GLP-1, so the GLP-1 stays in the blood longer. In response, the body makes more insulin and less glucagon than it would without Januvia or Onglyza. Together, these actions lower the blood sugar level.
More Answers from Jack Merendino, MD