Sitagliptin phosphate, a dipeptidyl peptidase-4 (DPP-4) inhibitor, is one of the most effective anti-hyperglycemic agents which has been included in the list of diabetes drugs since 2006 with the FDA approval2.The use of sitagliptin phosphate effectively reduces the fasting glucose and glycosylated hemoglobin A1C (HbA1c) levels in type II diabetic patients3. This evidence concerns the gene DPP4 and diabetes mellitus.