Janumet (Sitagliptin and Metformin)

Janumet is a combination tablet of sitagliptin and metformin used, along with diet and exercise, to control blood sugar in adults with type 2 diabetes. This guide covers janumet uses, how it works, dosage, side effects, precautions, drug interactions, use in pregnancy and breastfeeding and its approximate price in India.

What is Janumet?

Janumet combines two medicines for type 2 diabetes in one tablet: sitagliptin and metformin. It is used together with diet and exercise to help control blood sugar in adults. Because it contains two medicines, it is generally used when both are appropriate for the person, for example when blood sugar is not adequately controlled with one of them alone, or when someone already takes both separately. It should be used only under a doctor’s supervision.

How Janumet Works

• Sitagliptin: Sitagliptin inhibits the enzyme DPP-4, which slows the breakdown of incretin hormones such as GLP-1 (glucagon-like peptide-1) and GIP. This increases insulin release and decreases glucagon in a glucose-dependent way, which reduces glucose production by the liver.
• Metformin: Metformin decreases glucose production by the liver, decreases glucose absorption from the intestine and improves insulin sensitivity by increasing glucose uptake and use in muscle and other tissues.

Together they act on different mechanisms behind high blood sugar in type 2 diabetes.

When Janumet Is Used

• Type 2 diabetes in adults: The US label covers use as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes. It is generally used when blood sugar is not adequately controlled with metformin or sitagliptin alone, or in people already taking both medicines separately.
• Limits of use: Janumet should not be used in type 1 diabetes. It has not been studied in people with a history of pancreatitis, and it is unknown whether they are at increased risk of pancreatitis while using it.
• Lifestyle remains important: Janumet is not a substitute for diet and exercise.

Janumet Dosage and How to Take It

Dosing is individualized by your doctor based on your current regimen, how well it works and how well you tolerate it. The examples below come from the US prescribing information. Janumet and Janumet XR have separate labels, so they are described separately. This is general information only.

Janumet (immediate-release tablets, 50/500 mg and 50/1000 mg)

• How to take it: Take Janumet orally twice daily with meals. Do not split or divide the tablets.
• Starting dose if not on metformin: 50 mg sitagliptin and 500 mg metformin twice daily, with gradual dose increases to reduce metformin’s stomach side effects.
• Starting dose if already on metformin: sitagliptin 50 mg twice daily (100 mg total daily) together with the metformin dose already being taken. For example, for someone taking metformin 850 mg twice daily, the label suggests 50 mg sitagliptin and 1000 mg metformin twice daily.
• Maximum daily dose: 100 mg of sitagliptin and 2000 mg of metformin.

Janumet XR (extended-release tablets)

• How to take it: Take Janumet XR once daily with a meal. If you are prescribed two tablets, take them together. Do not split, crush or chew the tablets.
• Strengths: 50 mg/500 mg, 50 mg/1000 mg and 100 mg/1000 mg (extended-release).
• Starting dose if not on metformin: 100 mg sitagliptin and 1000 mg metformin extended-release once daily, increased gradually.
• Starting dose if already on metformin: 100 mg sitagliptin plus the metformin dose already being taken, once daily. For people taking immediate-release metformin 850 mg or 1000 mg twice daily, the label suggests two 50 mg/1000 mg Janumet XR tablets taken together once daily.
• Switching products: When changing between Janumet and Janumet XR, the same total daily dose of sitagliptin and metformin is maintained, but the number of tablets and how often they are taken differ. Your doctor will direct any switch.
• Maximum daily dose: 100 mg of sitagliptin and 2000 mg of metformin extended-release.

Kidney function (both products)

• Doctors assess kidney function (eGFR) before starting and periodically afterward. The label advises at least yearly assessment, more often for people at higher risk such as older adults.
• Contraindicated: eGFR below 30 mL/min/1.73 m².
• Janumet (immediate-release): Not recommended when eGFR is 30 to below 45, because these patients need a lower sitagliptin dose than the fixed combination provides.
• Janumet XR: Starting treatment is not recommended when eGFR is 30 to 45. If eGFR later falls below 45, the doctor assesses the benefit and risk of continuing and limits the sitagliptin component to 50 mg once daily. Stop if eGFR falls below 30.

Iodinated contrast imaging (both products)

• Janumet may need to be stopped at the time of, or before, an iodinated contrast imaging procedure in people with eGFR between 30 and 60 mL/min/1.73 m², in people with a history of liver disease, alcoholism or heart failure, and in anyone who will receive intra-arterial iodinated contrast.
• Kidney function (eGFR) is re-evaluated 48 hours after the procedure, and Janumet is restarted only if kidney function is stable. Your prescribing doctor decides when to stop and restart.

Children: Janumet and Janumet XR are indicated for adults. Safety and effectiveness in pediatric patients have not been established.

Take this medicine only as advised by your doctor or healthcare professional. Do not start, stop, or change the dose on your own.

Side Effects of Janumet

Common effects may include:

• Diarrhea, nausea, vomiting, gas, indigestion and abdominal discomfort (mostly from metformin, and often improved by gradual dose increases and taking tablets with meals)
• Upper respiratory tract infection, stuffy or runny nose and sore throat
• Headache and tiredness (asthenia)

Serious effects need prompt medical attention:

• Lactic acidosis (boxed warning): Symptoms can start subtly, such as feeling unwell (malaise), muscle pain, trouble breathing, unusual sleepiness and abdominal pain. In severe cases a low body temperature, low blood pressure and slow or irregular heartbeat can occur. Stop Janumet and get emergency care if suspected.
• Pancreatitis: persistent severe abdominal pain, sometimes spreading to the back, with or without vomiting. Stop Janumet and contact your doctor right away.
• Heart failure: shortness of breath, swollen ankles or feet, unusual tiredness or sudden weight gain
• Acute kidney problems: worsening kidney function, sometimes needing dialysis, has been reported after approval
• Severe allergic reactions: swelling of the face, lips, tongue or throat, trouble breathing, widespread rash, or blistering or peeling skin (including Stevens-Johnson syndrome). These typically began within the first 3 months of sitagliptin treatment, sometimes after the first dose.
• Severe and disabling joint pain
• Bullous pemphigoid: blisters or erosions on the skin
• Low blood sugar (hypoglycemia): shakiness, sweating, hunger or confusion, more likely with insulin or a sulfonylurea
• Low vitamin B12: with long-term metformin, which can sometimes be linked to anemia

Janumet Precautions and Monitoring

Contraindications (Janumet should not be used):

• Severe renal impairment (eGFR below 30 mL/min/1.73 m²)
• Acute or chronic metabolic acidosis, including diabetic ketoacidosis
• A history of a serious hypersensitivity reaction (such as anaphylaxis or angioedema) to Janumet, sitagliptin or metformin

Situations needing caution or doctor reassessment:

• Lactic acidosis risk factors: renal impairment, age 65 or older, liver impairment, excessive alcohol intake, certain medicines (such as topiramate and other carbonic anhydrase inhibitors), iodinated contrast imaging, surgery and other procedures, and low-oxygen states such as acute heart failure, shock, heart attack or sepsis. Janumet is stopped if such an event occurs. The current Janumet XR label also lists mitochondrial diseases (such as MELAS and MIDD) as a risk factor and does not recommend use in them.
• Liver disease: Avoid use in people with clinical or laboratory evidence of hepatic disease, because lactic acidosis cases have occurred in people with liver impairment.
• Heart failure: An association between DPP-4 inhibitor treatment and heart failure was seen in cardiovascular outcomes trials of two other medicines in this class, in people with type 2 diabetes and cardiovascular disease. Doctors weigh the risks and benefits before starting Janumet in people at risk of heart failure (such as those with prior heart failure or kidney impairment) and watch for symptoms.
• Pancreatitis: The label reports postmarketing cases, including fatal and non-fatal severe pancreatitis. Stop Janumet promptly if pancreatitis is suspected, and tell your doctor if you have ever had pancreatitis.
• Surgery and procedures: Janumet should be temporarily stopped while you have restricted food and fluid intake.
• Dehydration or acute illness: Severe vomiting, diarrhea or fever can affect your kidneys, so contact your doctor for advice on whether to pause treatment.
• Alcohol: Alcohol increases the effect of metformin on lactate, so avoid excessive alcohol intake.
• Monitoring: Doctors check kidney function before starting and at least yearly (more often if you are at risk), and the label advises checking blood counts annually and vitamin B12 every 2 to 3 years.
• Hypoglycemia: When combined with insulin or a sulfonylurea, a lower dose of those medicines may be needed.

Janumet Drug Interactions

Interactions are not all absolute, and your doctor will decide what is appropriate.

• Carbonic anhydrase inhibitors (topiramate, zonisamide, acetazolamide, dichlorphenamide): can increase the risk of lactic acidosis, so doctors may monitor more often.
• Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir and cimetidine): can increase metformin levels. Doctors weigh the benefits and risks.
• Alcohol: increases the effect of metformin on lactate metabolism.
• Insulin and sulfonylureas: raise the risk of low blood sugar, so lower doses may be needed.
• Medicines that can raise blood sugar (such as thiazide and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers and isoniazid): can lead to loss of blood sugar control, so your blood sugar may need closer monitoring.
• Iodinated contrast dye: Janumet may need to be stopped around the procedure (see Dosage).

Tell your doctor and pharmacist about all prescription medicines, over-the-counter medicines, supplements and herbal products you take. This list is not complete.

Janumet in Pregnancy and Breastfeeding

• Pregnancy: The limited data with Janumet in pregnant women are not enough to inform a risk of major birth defects or miscarriage. Published studies of metformin in pregnancy have not reported a clear association with birth defects or miscarriage, but they cannot rule out risk. Poorly controlled diabetes in pregnancy carries risks for mother and baby. Talk to your doctor if you are pregnant or planning pregnancy, because your treatment may need to change. Do not stop your diabetes medicine on your own. Metformin may also restart ovulation in some women who do not ovulate regularly, so discuss the chance of unintended pregnancy with your doctor.
• Breastfeeding: There is no information on Janumet in breast milk. Limited studies report that metformin is present in human milk, with no reports of adverse effects in breastfed infants, and sitagliptin is present in rat milk and so may be in human milk. Your doctor will weigh the benefits of breastfeeding and your need for treatment against possible effects on the infant. Do not stop medicines or breastfeeding on your own.

Janumet Brands, Strengths and Approximate Price in India

Examples of sitagliptin and metformin brands marketed in India include Janumet and Istamet, based on pharmacy listings. This is not an exhaustive list, and availability can change. Brands and strengths are not automatically interchangeable, so confirm any change with your pharmacist or prescribing doctor. Listings show tablets of 50 mg sitagliptin with 500 mg or 1000 mg metformin, and some listings also show a 50 mg/850 mg strength. Janumet XR is the extended-release product, and its availability and price in India were not verified.

The Janumet figures come from a pharmacy listing last updated on 5 October 2026. The Istamet figures differ between pharmacy listings.

Approximate price in India: ₹151–₹397 per strip of 15 tablets (listing-based; the range includes a small allowance for price variation between listings)

These are listing-based figures, not guaranteed current MRPs. Prices may vary by brand, strength, pack size, pharmacy, location and date, and availability can change.

How HealthPil Can Help

Medicines should be started, adjusted, or stopped only under the guidance of a qualified healthcare professional. If you have questions about Janumet, its side effects or your diabetes treatment plan, you can consult a doctor through HealthPil, including endocrinologists and diabetes specialists.