What is Sitagliptin used for?

Sitagliptin is evaluated for the following indications with varying evidence strength: Type 2 diabetes mellitus (evidence tier B), Weight loss (evidence tier F). See the full indication matrix with dosing and citations above on this page.

What are the side effects of Sitagliptin?

Common side effects of Sitagliptin (≥ 1 in 100): Nasopharyngitis, Headache, Abdominal pain, Constipation, Hypoglycemia with sulfonylureas. See the Safety section for uncommon and serious reactions.

Who should not take Sitagliptin?

Sitagliptin is contraindicated in: Sitagliptin hypersensitivity; Type 1 diabetes; Diabetic ketoacidosis; Severe hepatic impairment (use with caution). Full list in the Safety section.

Second-line in type 2 diabetes per / 2024 and SED 2023. First-line is metformin combined with GLP-1 agonists and/or SGLT2 inhibitors when cardiovascular or renal disease is present. Sitagliptin is considered as add-on to metformin in patients without major cardiovascular risk and without obesity, where tolerability and low hypoglycemia risk are priorities. In TECOS, it did not raise heart failure hospitalization risk in T2D patients with cardiovascular disease (unlike saxagliptin).

Weight loss

Not recommended

Sitagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor antidiabetic. It is prescribed for type 2 diabetes ( 2024, 2024). In people without diabetes, sitagliptin is not indicated for weight loss: the drug has a neutral effect on weight and is not approved for obesity treatment. The drug has specific risks: pancreatitis (rare but dangerous), arthralgia, and upper respiratory infections. If sitagliptin was prescribed for weight loss without diabetes, consider seeking a second opinion.

Sources

Timing and administration

Take 100 mg once daily, with or without food. In CKD, adjust: 50 mg at eGFR 30–45 and 25 mg at eGFR under 30. Do not combine with GLP-1 agonists – both potentiate incretin signaling without added benefit. With sulfonylureas, watch for hypoglycemia risk; the sulfonylurea dose usually needs reduction.

Contraindications

Sitagliptin hypersensitivity
Type 1 diabetes
Diabetic ketoacidosis
Severe hepatic impairment (use with caution)

Serious adverse effects

Acute pancreatitis
Severe allergic reactions, angioedema, Stevens–Johnson syndrome
Bullous pemphigoid
Severe arthralgia (FDA-described, 2015)
Acute kidney injury

Common adverse effects

Nasopharyngitis
Headache
Abdominal pain
Constipation
Hypoglycemia with sulfonylureas

PregnancyFDA B

Limited pregnancy data. Insulin is the foundation in pregnant T2D patients; oral antidiabetics are usually discontinued.

Breastfeeding

No data on milk excretion. Use during lactation is not recommended.

Calculate RID Full profile on NIH LactMed ↗

Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.

Sitagliptin

Mechanism of action

Indications

Type 2 diabetes mellitus

Marketing claims without evidence base

Weight loss

Practical notes

Timing and administration

Check interaction with another drug

Official sources

Safety