Information last reviewed: May 2026 — for educational purposes only.
What Is Januvia (Sitagliptin)?
Sitagliptin, branded as Januvia, is an oral DPP-4 inhibitor (dipeptidyl peptidase-4 inhibitor) used to treat type 2 diabetes mellitus. It works by inhibiting the enzyme DPP-4, which normally degrades the incretin hormones GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). By protecting these hormones from breakdown, sitagliptin enhances glucose-stimulated insulin secretion from pancreatic beta cells and suppresses glucagon release from alpha cells — both in a glucose-dependent manner, meaning it only acts when blood sugar is elevated, conferring a low intrinsic hypoglycaemia risk.
Prescription (Rx) Status
Januvia/sitagliptin is prescription-only. It is available in the US as the brand Januvia (Merck) and a generic was approved in 2023. Dose adjustment is required in patients with moderate-to-severe renal impairment (CKD stages 3–5). Sitagliptin is also available in the combination tablet Janumet (sitagliptin + metformin).
Uses of Sitagliptin
Sitagliptin is indicated as an adjunct to diet and exercise to improve glycaemic control in adults with type 2 diabetes. It may be used as monotherapy or combined with metformin, TZDs, sulfonylureas, or insulin. It is weight-neutral (no significant weight gain or loss), making it suitable for patients concerned about weight effects of antidiabetic agents.
Tablet Strengths
Januvia/sitagliptin oral tablets: 25 mg, 50 mg, and 100 mg. Standard dose in patients with normal renal function: 100 mg once daily. Dose reduction to 50 mg daily (moderate CKD) or 25 mg daily (severe CKD) is required. Tablets may be taken with or without food.
Price
Branded Januvia is expensive — approximately $400–$600/month without insurance. Generic sitagliptin (approved 2023) is considerably cheaper. Patient assistance programmes from Merck may provide Januvia at reduced cost for qualifying patients.
Frequently Asked Questions
Q: Does Januvia cause hypoglycaemia?
A: Rarely, when used as monotherapy. Risk increases when combined with sulfonylureas or insulin — in those combinations, dose reduction of the secretagogue may be warranted.
Q: Can sitagliptin cause pancreatitis?
A: There is a rare but reported association between DPP-4 inhibitors and pancreatitis. Discontinue and contact your doctor if severe abdominal pain develops.
Q: Is Januvia safe long-term?
A: The TECOS cardiovascular outcomes trial showed sitagliptin is cardiovascularly neutral. It is considered safe for long-term use with regular monitoring.
Disclaimer: This page is for informational purposes only and does not constitute medical advice. Sitagliptin requires a valid prescription. Always consult a qualified healthcare professional. See our full disclaimer.