9 Janumet Side Effects You Should Know About
Janumet is a medication for Type 2 diabetes. Side effects include digestive issues and headaches. See more side effects of Janumet and learn how to manage them.
Janumet
Used for Diabetes Type 2
Used for Diabetes Type 2
Janumet (sitagliptin / metformin) is a medication for adults with Type 2 diabetes. It contains two different diabetes medications that work together to help control blood sugar. One is sitagliptin, a DPP-4 inhibitor, and the other is metformin, a biguanide. The Janumet immediate-release tablets are taken by mouth twice a day. It works best when used with a balanced meal plan and exercise routine. Some side effects are diarrhea, upper respiratory tract infection, and headache. There's only a brand-name version of Janumet; there's no generic version yet.
What is Janumet (sitagliptin / metformin)?
What is Janumet (sitagliptin / metformin) used for?
How Janumet (sitagliptin / metformin) works
Janumet (sitagliptin / metformin) is a combination of two diabetes medications. It works to help lower blood sugar.
- Sitagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor. It blocks the action of DPP-4, a protein that normally breaks down insulin in the body. By blocking DPP-4, insulin can stick around in the body longer. It also stops your body from making glucagon, a hormone that raises blood sugar. This helps control your blood sugar levels.
- Metformin is a biguanide that works in a few ways. It stops the liver from making sugar. And it lowers the amount of sugar your body absorbs from food. Metformin also helps your body use its natural insulin better.
When does Janumet (sitagliptin / metformin) start working?Time passed since treatment started:
Drug facts
| Common Brands | Janumet |
|---|---|
| Drug Class | DPP-4 inhibitor / Biguanide |
| Controlled Substance Classification | Not a controlled medication |
| Generic Status | No lower-cost generic available |
| Availability | Prescription only |
More on Janumet (sitagliptin / metformin) essentials
Side effects of Janumet (sitagliptin / metformin)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Diarrhea (8%)
- Upper respiratory tract infection (6%)
- Headache (6%)
Less Common Side Effects
- Nausea
- Vomiting
- Stomach pain
Janumet (sitagliptin / metformin) serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Inflammation of the pancreas (pancreatitis): upper belly pain that spreads to your back, nausea, vomiting
- Buildup of lactic acid in the body: rapid breathing, fast heartbeat, feeling weak or tired, nausea, stomach pain, muscle pain, confusion
- Kidney problems: urinating less, itching, swelling of the ankles or feet
- Heart failure: shortness of breath, unusually fast weight gain, swelling of the legs or feet
- Severe allergic reaction: hives, blisters, trouble breathing, swelling of the face or throat
More on Janumet (sitagliptin / metformin) side effects
The following Janumet (sitagliptin / metformin) side effects have also been reported
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Less common
blurred vision
chills
cold sweats
confusion
cool, pale skin
dizziness
fast heartbeat
headache
increased hunger
loss of consciousness
mental cloudiness
nightmares
not thinking clearly
seizures
shakiness
slurred speech
unusual tiredness or weakness
Rare
Decreased appetite
fast, shallow breathing
general feeling of discomfort
muscle pain or cramping
sleepiness
stomach discomfort
Incidence not known
Blistering, peeling, or loosening of the skin
darkened urine
hives or welts, itching, or skin rash
large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
loss of appetite
pains in the stomach, side, or abdomen, possibly radiating to the back
puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
red skin lesions, often with a purple center
severe joint pain
sores, ulcers, or white spots in the mouth or on the lips
vomiting
yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Bloated or feeling of fullness
excess air or gas in the stomach or intestines
indigestion
lack or loss of strength
muscle aches
passing gas
stuffy or runny nose
vomiting
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Get your GoodRx coupon
$429.04
GoodRx discount
$329.00
Pros and cons of Janumet (sitagliptin / metformin)
Pros
- Combines the effects of two diabetes medications into one tablet
- Less likely to cause weight gain and low blood sugar compared to other diabetes medications
- Can lower A1C by up to 2% in 6 months
Cons
- Must take twice a day with meals
- Only available as a fixed dose, so can be hard to make dose adjustments
- Not a good option for people with severe kidney problems
- Not approved for people with Type 1 diabetes
Pharmacist tips for Janumet (sitagliptin / metformin)
- Swallow the Janumet (sitagliptin / metformin) tablet whole. Don't split, cut, crush, or chew it. Speak to your prescriber if you have trouble swallowing pills whole.
- Take Janumet (sitagliptin / metformin) with a meal. This helps lower the risk of side effects like nausea and diarrhea.
- Check your blood sugar regularly as your diabetes care team told you to. Write down your results and share them with your prescriber. This helps them see how well the medication is working for you. It also helps them figure out the diabetes treatment plan that works best for you.
- It's a good idea to avoid alcohol while taking Janumet (sitagliptin / metformin). Alcohol can sometimes make some side effects, like headaches and stomach upset, worse. Also, drinking too much alcohol with this medication can put you at risk of a very serious condition called lactic acidosis. Talk to your prescriber about how much alcohol you drink.
- Let your healthcare team know if you're going to have surgery or an imaging test or if you've had one in the past 2 days. Janumet (sitagliptin / metformin) can interact with contrast dyes that some procedures use. This can cause problems for your kidneys. Your care team can tell you if you need to stop taking the medication before your procedure and when it's safe to start taking it again.
- Along with taking Janumet (sitagliptin / metformin), it's important to eat a balanced diet and exercise regularly as part of your diabetes treatment plan. When you do all three, it helps improve your blood sugar. This helps you get the most out of your treatment. Ask your care team about how to best manage your diabetes.
Risks and warnings for Janumet (sitagliptin / metformin)
Janumet (sitagliptin / metformin) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Lactic acidosis
- Risk factors: Kidney problems | Liver problems | Heart problems | Age 65 or older | Drinking a lot of alcohol | People with food or fluid restrictions | Using contrast dye for surgery or other procedures
Janumet contains metformin. Although rare, metformin can cause a serious condition called lactic acidosis (too much lactic acid in the blood). This condition can lead to other health problems that can be life-threatening. Tell your prescriber about your medical history and your other medications before you start treatment. They can check if you're at risk of lactic acidosis.
Call your care team right away if you notice fast breathing, trouble breathing, an unusual heartbeat, a very upset stomach, or muscle pain. Also reach out if you feel very sleepy, tired, weak, dizzy, or cold. These can be signs that you have too much lactic acid in your blood. Your care team can work to help treat this condition.
Inflammation of the pancreas (pancreatitis)
Although rare, some people taking Janumet (sitagliptin / metformin) had an inflamed pancreas (pancreatitis). It's not clear if people who've had pancreatitis before are more likely to get it again with treatment. To be safe, tell your prescriber if you've had pancreatitis before.
Stop taking Janumet (sitagliptin / metformin) and get medical help right away if you feel belly pain that won't go away or that spreads to your back. This can happen with or without nausea and vomiting. These can be signs of pancreatitis that a healthcare professional should check out.
Risk of heart failure
- Risk factors: History of heart failure | History of kidney issues
Some clinical studies found that there might be a link between DPP-4 inhibitor (like sitagliptin) and heart failure. People in these studies had or were at risk of heart disease.
It's not clear if Janumet (sitagliptin / metformin) raises the risk of heart failure. To be safe, tell your prescriber about your full medical history before starting this medication. This is especially important if you have a history of or are at risk of heart failure. They can help you understand the risks and benefits of treatment.
Get medical help right away if you notice any symptoms related to heart failure. This includes shortness of breath, fast or irregular heartbeat, swelling in the ankles or feet, rapid weight gain, and chest pain.
Sudden kidney problems
- Risk factors: Older adult | History of kidney issues
Some people had worsening kidney function while taking Janumet (sitagliptin / metformin). In some cases, acute (sudden) kidney failure happened and people needed dialysis to manage it.
Tell your prescriber about all your health problems before starting Janumet (sitagliptin / metformin). This medication isn't a good choice for people with severe kidney issues. During treatment, your prescriber will check your blood regularly. This helps them make sure your kidneys are okay. If your kidneys get worse, you might need to stop taking the medication.
Low vitamin B12 levels
- Risk factors: Long-term use of Janumet (sitagliptin / metformin) | Lower than average calcium absorption | Lower than average vitamin B12 absorption
The metformin in Janumet can lower how much vitamin B12 your body absorbs. This can make your vitamin 12 levels drop, which could lead to anemia (a low red blood cell count). To be safe, your prescriber might check for low vitamin B12 and anemia with a blood test every 1 to 3 years.
Tell your care team if you feel tired or dizzy, have weak muscles, or feel tingling or numbness. These could be signs of low vitamin B12. If blood tests show your levels are low, your prescriber might recommend a vitamin B12 supplement to get your levels back up.
Low blood sugar (hypoglycemia) when taken with certain diabetes medications
- Risk factors: Also using insulin | Also taking sulfonylureas like glipizide
When you take Janumet (sitagliptin / metformin) with certain other diabetes medications, you have a higher chance of low blood sugar (hypoglycemia). These diabetes medications are insulin and sulfonylureas like glipizide. Very low blood sugar can be dangerous.
Be sure you know how to recognize and treat low blood sugar. Look for symptoms like feeling shaky, very hungry, confused, or weak. You also might be nervous or anxious, have a fast heartbeat, or sweat. Talk to your healthcare team if you're worried about having low blood sugar while taking Janumet (sitagliptin / metformin).
Joint pain
Some people who've taken a DPP-4 inhibitor like the sitagliptin in Janumet have had severe and disabling joint pain. This has happened within one day to years after starting this medication. For most people, the pain goes away after they stop taking it. Talk to your prescriber right away if you feel any discomfort in your joints.
Severe skin reaction
Some people who've taken a DPP-4 inhibitor, like the sitagliptin in Janumet, have had a skin reaction called bullous pemphigoid. It looks like an itchy, blistering rash. Usually, the blisters or sores go away once you stop taking the medication and get treated.
Talk to your care team if you have itchy skin, a rash with blisters, or sores while taking Janumet (sitagliptin / metformin). You might need to stop taking the medication and see a dermatologist.
Serious allergic reactions
Although it's rare, some people can have a serious allergic reaction to Janumet (sitagliptin / metformin). This can include life-threatening reactions like peeling, blistering skin and anaphylaxis. Allergic reactions most often happen within the first 3 months of treatment. But they can also happen at any time.
Be sure to tell your prescriber if you've had an allergic reaction to other DPP-4 inhibitors or "gliptins." Examples are Januvia (sitagliptin) and saxagliptin (Onglyza). It's not clear if you might have an allergic reaction if you take Janumet (sitagliptin / metformin).
Stop taking Janumet (sitagliptin / metformin) and get medical help right away if you have an allergic reaction. Look out for a widespread rash, hives, blisters, peeling skin, trouble breathing, or swelling in your face or throat.
Janumet (sitagliptin / metformin) dosage
The average cost for 60 tablets of 50mg/1000mg of Janumet (sitagliptin / metformin) is $329.00 with a free GoodRx coupon. This is 23.32% off the average retail price of $429.04. 
Tablet
Tablet| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 50mg/500mg | 60 tablets | $329.30 | $5.49 |
| 50mg/1000mg | 60 tablets | $329.00 | $5.48 |
Typical dosage for Janumet (sitagliptin / metformin)
The typical starting dose is 50 mg/500 mg (sitagliptin/metformin) by mouth twice daily with meals.
Your dose might differ if you were taking metformin by itself before you started Janumet.
The maximum daily dose for Janumet is 100 mg/2,000 mg (sitagliptin/metformin).
More on Janumet (sitagliptin / metformin) dosage
Interactions between Janumet (sitagliptin / metformin) and other drugs
Janumet (sitagliptin / metformin) may interact with certain medications or supplements. Always let your doctor and pharmacist know about any other medications or supplements (including prescribed and over-the-counter medications, vitamins, and dietary or herbal supplements) that you are currently taking. The list below does not include all possible drug interactions with Janumet (sitagliptin / metformin). Please note that only the generic name of each medication is listed below.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Acetrizoic Acid
- Diatrizoate
- Ethiodized Oil
- Iobenzamic Acid
- Iobitridol
- Iocarmic Acid
- Iocetamic Acid
- Iodamide
- Iodipamide
- Iodixanol
- Iodohippuric Acid
- Iodopyracet
- Iodoxamic Acid
- Ioglicic Acid
- Ioglycamic Acid
- Iohexol
- Iomeprol
- Iopamidol
- Iopanoic Acid
- Iopentol
- Iophendylate
- Iopromide
- Iopronic Acid
- Ioseric Acid
- Iosimide
- Iotasul
- Iothalamate
- Iotrolan
- Iotroxic Acid
- Ioxaglate
- Ioxitalamic Acid
- Ipodate
- Metrizamide
- Metrizoic Acid
- Tyropanoate Sodium
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Acarbose
- Aspirin
- Balofloxacin
- Besifloxacin
- Bupropion
- Capmatinib
- Chloroquine
- Chlorpropamide
- Ciprofloxacin
- Dasabuvir
- Dofetilide
- Dolutegravir
- Enoxacin
- Fleroxacin
- Flumequine
- Gatifloxacin
- Gemifloxacin
- Glimepiride
- Glipizide
- Glyburide
- Hydroxychloroquine
- Ioversol
- Lanreotide
- Levofloxacin
- Lomefloxacin
- Metformin
- Moxifloxacin
- Nadifloxacin
- Nateglinide
- Norfloxacin
- Octreotide
- Ofloxacin
- Ombitasvir
- Paritaprevir
- Pasireotide
- Pazufloxacin
- Pefloxacin
- Pioglitazone
- Prulifloxacin
- Repaglinide
- Ritonavir
- Rufloxacin
- Simeprevir
- Sitagliptin
- Sparfloxacin
- Tafenoquine
- Thioctic Acid
- Tolazamide
- Tolbutamide
- Tosufloxacin
- Vandetanib
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Acebutolol
- Atenolol
- Betaxolol
- Bisoprolol
- Bitter Melon
- Carteolol
- Carvedilol
- Celiprolol
- Colesevelam
- Esmolol
- Fenugreek
- Furazolidone
- Glucomannan
- Guar Gum
- Iproniazid
- Isocarboxazid
- Labetalol
- Levobunolol
- Linezolid
- Methylene Blue
- Metipranolol
- Metoprolol
- Moclobemide
- Nadolol
- Nebivolol
- Nialamide
- Oxprenolol
- Patiromer
- Penbutolol
- Phenelzine
- Pindolol
- Practolol
- Procarbazine
- Propranolol
- Psyllium
- Ranolazine
- Rasagiline
- Rifampin
- Safinamide
- Selegiline
- Sotalol
- Timolol
- Tranylcypromine
- Verapamil
How much does Janumet (sitagliptin / metformin) cost?
To access savings, use a GoodRx coupon and pay just a fraction of the retail price.
Janumet (brand)
$329.00
Janumet (sitagliptin / metformin) contraindications
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Janumet (sitagliptin / metformin) will not be safe for you to take.
- Poor kidney function
- Metabolic acidosis (including diabetic ketoacidosis)
- Allergic reaction to sitagliptin or metformin
What are alternatives to Janumet (sitagliptin / metformin)?
There are a number of medications that your doctor can prescribe in place of Janumet (sitagliptin / metformin). Compare a few possible alternatives below.
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Janumet (sitagliptin / metformin) images
