Nateglinide D5 is a deuterium labeled Nateglinide. Nateglinide, a D-phenylalanine derivative, is an orally active and short-acting insulinotropic agent and a DPP IV inhibitor. Nateglinide inhibits ATP-sensitive K+ channels in pancreatic β-cells. Nateglinide is used for the treatment of type 2 (non-insulin-dependent) diabetes mellitus[2].