1.NounA hypoglycemic drug taken orally in the form of its phosphate C16H15F6N5O·H3PO4·H2O in the treatment of type 2 diabetes. It acts by inhibiting the degradation of incretins, which results in increased secretion of insulin by the pancreas. It is marketed under the trademark Januvia and when used in combination with metformin, under the trademark Janumet.