Sitagliptin- junuvia- msd - is an oral antihyperglycemic (antidiabetic drug) of the dipeptidyl peptidase-4 (dpp-4) inhibitor class recommended in type ii diabetes . It is recommended with diet & exercise and sometimes with other medications to lower blood sugar levels in patients with type 2 diabetes. It works by increasing the amounts of certain natural substances that lower blood sugar when it is high.