Janumet XR 50/500mg is a prescription medication containing sitagliptin and metformin HCl in extended-release form. This combination medication comes in a package of 56 tablets and is used to help control blood sugar levels in patients with type 2 diabetes. Each tablet contains 50mg sitagliptin and 500mg metformin hydrochloride in an extended-release formulation. The XR (extended-release) formulation allows for once-daily dosing. This medication should be taken as prescribed by your healthcare provider and used in conjunction with diet and exercise for optimal blood sugar control.