metformin/sitagliptin
Brand names: Janumet
Janumet XR is a drug that combines sitagliptin and metformin. It helps lower blood sugar in adults with type 2 diabetes, along with diet and exercise.
Drug Pricing (NADAC)
Brand Price
$9.17/unit
Generic Available
No
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Janumet XR is used to help control blood sugar levels in adults who have type 2 diabetes.
Common side effects
Diarrhea, Upper respiratory infection, Headache
Key warnings
Metformin can cause a rare but serious side effect called lactic acidosis.
How It Works
Janumet XR contains two medicines. Sitagliptin helps your body release more insulin after you eat. Metformin helps your body use insulin better and reduces sugar production in the liver.
How to Take It
Take Janumet XR once a day with a meal. If you take two tablets, take them together at the same time. Your doctor will adjust your dose based on how well the medicine works for you. Do not crush, split, or chew the tablets.
Pregnancy & Breastfeeding
Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if Janumet XR will harm your unborn baby. Talk to your doctor if you are breastfeeding or plan to breastfeed.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and take your next dose at the regular time.
Storage
Store Janumet XR at room temperature (68-77°F) in a dry place, and keep the cap tightly closed.
Side Effects (from patient reports)
Based on 171,728 FDA adverse event reports.
Serious Warnings
Metformin can cause a rare but serious side effect called lactic acidosis. Get medical help right away if you have symptoms like feeling very weak, muscle pain, trouble breathing, stomach pain, dizziness, or a slow or irregular heartbeat. Certain conditions increase your risk, such as kidney problems, drinking too much alcohol, or having surgery.
Known Drug Interactions
Drug Interactions The concomitant use of JANUMET XR with specific drugs may increase the risk of metformin-associated lactic acidosis: those that impair renal function, result in significant hemodynamic change, interfere with acid-base balance or increase metformin accumulation [see Drug Interactions (7) ]. Drugs that Reduce Metformin Clearance Clinical Impact: Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT 2 ] / multidrug and toxin extrusion [MATE] inhibitors) coul...
Mechanism: Both of these medications contain metformin, so taking them together results in a double dose of the same ingredient. This significantly increases the risk of a dangerous buildup of acid in your bloodstream.
What to do: Avoid taking these two medications together. Your doctor or pharmacist should ensure you are only taking one product that contains metformin to prevent an overdose.
Examples: Topiramate, zonisamide, acetazolamide or dichlorphenamide.
Mechanism: Topiramate changes how your body handles acid in the blood, which can increase the risk of side effects from metformin.
What to do: Your healthcare provider may need to check your blood chemistry more often while you take these drugs together.
Examples: Ranolazine, vandetanib, dolutegravir, and cimetidine. ( 7 ) Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin.
Mechanism: Dolutegravir slows down the process of removing metformin from your body, which can cause the drug to build up to high levels.
What to do: Your doctor may need to lower your metformin dose to avoid side effects.
Examples: Ranolazine, vandetanib, dolutegravir, and cimetidine. ( 7 ) Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin.
Mechanism: Ranolazine makes it harder for your kidneys to clear metformin out of your system, leading to higher amounts of the drug in your blood.
What to do: Your doctor should monitor you closely and might adjust your metformin dosage.
Examples: Ranolazine, vandetanib, dolutegravir, and cimetidine. ( 7 ) Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin.
Mechanism: Cimetidine blocks the way your body gets rid of metformin, which can cause metformin to reach unsafe levels in your body.
What to do: Your healthcare provider may need to adjust your metformin dose while you are taking cimetidine.
Common Questions
What should I do if I experience severe joint pain while taking Janumet XR?
Can Janumet XR be used to treat type 1 diabetes?
What should I do before having an X-ray or CT scan with contrast dye?
Does Janumet XR cause weight gain?
Can I drink alcohol while taking Janumet XR?
What happens if my kidney function gets worse while taking Janumet XR?
Can Janumet XR cause low blood sugar?
How often will my doctor check my kidney function?
What are the symptoms of lactic acidosis?
Can I cut the Janumet XR tablet in half?
What are the common side effects of metformin/sitagliptin?
Does metformin/sitagliptin interact with other medications?
What drug class is metformin/sitagliptin?
Is metformin/sitagliptin safe during pregnancy?
Related Medications in Biguanide / DPP-4 Combination
Other drugs grouped near metformin/sitagliptin — same-class peers and common alternatives.
acarbose
Precose
Acarbose is a medicine that helps lower blood sugar levels in people with type 2 diabetes.
Compare with metformin/sitagliptin →
alogliptin
Nesina
Alogliptin and Metformin HCl is a drug that helps lower blood sugar in adults with type 2 diabetes.
Compare with metformin/sitagliptin →
bromocriptine
Cycloset
Bromocriptine (Cycloset) is a medicine that acts like dopamine in your body.
Compare with metformin/sitagliptin →
canagliflozin
Invokana
Invokana is a medicine used with diet and exercise to lower blood sugar in adults with type 2 diabetes.
Compare with metformin/sitagliptin →
colesevelam
Welchol
Colesevelam is a medicine that helps lower bad cholesterol (LDL-C) and control blood sugar in adults.
Compare with metformin/sitagliptin →
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
Related Health & Safety Data
🩺 Find a Doctor
Search prescribers for Biguanide / DPP-4 Combination
🏨 Hospital Quality
CMS hospital ratings, safety scores & patient outcomes
💊 Supplement Data
NIH DSLD — check supplement ingredients & label claims
🍽️ Food Safety Alerts
FDA recalls, inspections & outbreak investigations
⚠️ Product Recalls
FDA, CPSC & NHTSA recall search
💉 Procedure Costs
Medicare procedure pricing for 9,297 procedures
Save on metformin/sitagliptin
Compare prices and find discounts at pharmacies near you. Free coupons can save up to 80% on prescriptions.
Disclosure: This link may earn us a commission at no extra cost to you. See our terms.
What the FDA Data Shows for metformin/sitagliptin
The FDA label for metformin/sitagliptin (sold under brand names such as Janumet) classifies it as a prescription-only medication in the Biguanide / DPP-4 Combination class. Janumet XR is used to help control blood sugar levels in adults who have type 2 diabetes. Official labeling lists 3 commonly reported side effects, including Diarrhea, Upper respiratory infection, Headache.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 171,728 voluntary reports. The database also lists 7 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS.
Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: March 25, 2025
Read our methodology — how this data is sourced, computed, and verified.
All federal data sources used on this page
- FDA Orange Book — approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed — NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) — post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm — standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files — federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database — current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages