If you have type 2 diabetes, your doctor might suggest Janumet or Janumet XR as a treatment option for you. They’re both prescription drugs used along with diet and exercise to treat type 2 diabetes in adults.
Janumet and Janumet XR both come in the form of a tablet you swallow. They contain the active ingredients sitagliptin and metformin. (An active ingredient is what makes a drug work.)
Janumet is typically taken twice per day, while Janumet XR is usually taken once per day. This is because Janumet XR contains an extended-release form of metformin. “Extended-release” means the drug releases slowly into your body over a longer period.
Janumet and Janumet XR are typically taken long term. Sitagliptin is currently available as the brand-name drug Januvia. A generic form may become available in a few years. Metformin and metformin extended-release are available as generic drugs, which are often cheaper than brand-name versions.
For more information about Janumet and Janumet XR, including details about their uses, see this in-depth article.
Like other drugs, Janumet and Janumet XR can cause mild to serious side effects. Because they both contain two drugs, side effects for both sitagliptin and metformin will be covered in this article. Keep reading to learn more.
Some people may experience mild to serious side effects during treatment with Janumet or Janumet XR. Examples of commonly reported side effects of these drugs include:
* To learn more about this side effect, see the “Side effects explained” section below.
These are just a few of the side effects these drugs may cause. And not everyone who takes these drugs will have side effects. Continue reading for more information on mild to serious side effects of Janumet and Janumet XR.
Some people who take Janumet or Janumet XR will have mild side effects. Examples that have been reported with these drugs include:
- low level of vitamin B12
- upper respiratory infection (a cold)
- diarrhea
- nausea
- belly pain
- vomiting
- headache*
* To learn more about this side effect, see the “Side effects explained” section below.
In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And don’t stop taking Janumet or Janumet XR unless your doctor recommends it.
These drugs may cause mild side effects other than those listed above. For details, see the prescribing information for Janumet and Janumet XR.
Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Janumet or Janumet XR, visit MedWatch.
People with liver, kidney, or heart problems are more likely to have serious side effects from Janumet and Janumet XR. Serious side effects that have been reported with these drugs include:
- pancreatitis (inflammation of the pancreas)
- severe joint pain
- heart failure
- kidney problems
- hypoglycemia*
- bullous pemphigoid*
- allergic reaction*
- risk of lactic acidosis†
If you develop serious side effects while taking Janumet or Janumet XR, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.
* To learn more about this side effect, see the “Side effects explained” section below.
† Janumet and Janumet XR have a
Get answers to some frequently asked questions about Janumet and Janumet XR’s side effects.
Is there an increased risk of side effects with the 50 mg/1,000 mg doses of Janumet and Janumet XR compared with lower strengths of these drugs?
Yes, the lower dose is less likely to cause side effects at first. This is why your dose is increased slowly over time. The 50-milligram (mg)/1,000-mg dosage refers to 50 mg of sitagliptin and 1,000 mg of metformin.
In order to reduce the belly pain, nausea, vomiting, and diarrhea side effects of metformin, your treatment is usually started at a low dose.
For example, if you’ve never taken metformin, your starting dosage of Janumet would be 50 mg sitagliptin/500 mg metformin taken twice daily. For Janumet XR, the initial dosage is typically 50 mg sitagliptin/500 mg metformin taken once daily. Then, your doctor may slowly increase your dosage over time.
Higher strengths of these drugs may not be safe for people with kidney problems due to the risk of side effects, such as lactic acidosis. If you have severe kidney problems, your doctor will likely not prescribe Janumet or Janumet XR for you.
Can Janumet and Janumet XR cause pancreatic cancer?
The manufacturer of Janumet and Janumet XR did not include pancreatic cancer as a side effect. But pancreatitis (inflammation of the pancreas) was reported in studies of Janumet and Janumet XR. This is a serious side effect that may lead to death.
Pancreatic cancer was reported in some studies of people who took sitagliptin, an active ingredient in Janumet and Janumet XR. (An active ingredient is what makes a drug work.) But this may have been because of other risk factors they had. It’s not clear whether there is a connection between sitagliptin and pancreatic cancer.
Do Janumet and Janumet XR cause hair loss or blurry vision?
Blurry vision is a possible sign of hypoglycemia (low blood sugar). Studies of Janumet and Janumet XR showed low blood sugar as a side effect. If you notice blurry vision, talk with your doctor about managing your blood sugar level. And be sure to have an eye exam to look for other conditions that could be causing your vision changes.
The drugs’ manufacturer did not report hair loss as a side effect of these drugs. If you have uncontrolled diabetes, you may have hair loss. This is a symptom of diabetes rather than a side effect of Janumet or Janumet XR.
How long do Janumet and Janumet XR side effects last?
It depends on the side effect. Diarrhea, nausea, and other digestion-related side effects are very common when you first start taking Janumet or Janumet XR. (This is the case with any medication that contains metformin). Taking your dose with a meal can help lessen these side effects. And they should go away within a few days to weeks as you continue treatment.
Janumet XR may be a better option than Janumet for people who continue to have digestion-related side effects. This is because Janumet XR contains an extended-release form of metformin, which is often easier to tolerate. (“Extended-release” means the drug releases slowly into your body over a longer period.)
Other side effects of Janumet or Janumet XR may go away more quickly if they’re treated. For example, headache is a common side effect that can be treated with a pain reliever such as ibuprofen or Tylenol.
If you have side effects from Janumet or Janumet XR that don’t go away or become severe, talk with your doctor.
Is weight loss a possible side effect of Janumet and Janumet XR?
Yes, weight loss is possible when you take Janumet or Janumet XR. Modest weight loss has been reported in people taking metformin. (Metformin is one of the active ingredients in Janumet and Janumet XR. An active ingredient is what makes the drug work.)
These medications are not approved for weight loss. If you lose weight while taking these drugs, you may gain the weight back if you stop taking them.
A healthy way to lose weight is to exercise and eat a nutritious diet. Janumet and Janumet XR are meant to be used along with diet and exercise to treat type 2 diabetes.
Learn more about some of the side effects Janumet and Janumet XR may cause.
Risk of lactic acidosis
Lactic acidosis is a rare but serious side effect of Janumet and Janumet XR severe enough to have a
Lactic acidosis is a condition where too much lactic acid builds up in your blood and tissues. This side effect was not reported in studies of Janumet and Janumet XR. But it was reported in studies of metformin, one of the active ingredients in these drugs. (An active ingredient is what makes a drug work.) This condition can lead to death if it’s not treated. It can also lead to other conditions, such as abnormal heart rhythms.
Certain factors can increase your risk of lactic acidosis. If you already have problems with your kidneys, liver, or heart, your risk may be higher. Drinking alcohol is also a risk factor. You can talk with your doctor about ways to decrease your risk of this serious side effect.
If you notice symptoms of lactic acidosis, contact a healthcare professional right away. If you think your life might be in danger, call 911 or your local emergency number. Some symptoms to look out for include:
- dizziness or lightheadedness
- trouble breathing
- weakness
- low appetite
- flushing (temporary warmth, redness, or deepening of skin color)
- muscle pain
- belly pain
- vomiting
- nausea
- increased blood levels of certain chemicals, including lactic acid
What might help
Lactic acidosis is a medical emergency. It will need to be treated at a medical facility. If you have this side effect, you’ll stop taking Janumet or Janumet XR.
If you have risk factors for lactic acidosis, you can take steps to help manage those risks. For example, if you have kidney problems, take your medication and keep up with blood tests and doctor visits. If you drink alcohol, decrease the amount you consume. Talk with your doctor about avoiding medications that may interact with metformin.
Hypoglycemia
Hypoglycemia (low blood sugar) is a rare side effect of Janumet and Janumet XR. It was reported in studies of people who were taking additional blood sugar-lowering medication at the same time, including insulin.
It’s important to catch low blood sugar before it becomes severe. The symptoms of mild low blood sugar can be easy to miss and include:
- sweating
- dizziness
- headache
- confusion
- trouble concentrating
- fast heartbeat
- blurry vision
- irritability
- shaking
Symptoms of very low blood sugar are more severe and can include:
What might help
You can check your blood sugar level several times per day using a glucometer (a medical device that measures blood sugar). There are many kinds of glucometers, some of which can be connected to a smartphone. So you can choose one that works best for your day-to-day life.
If you notice that your blood sugar is low, consume 15 grams (g) of sugar. This can be in the form of a glucose tablet or 4 ounces of juice or non-diet soda. Wait 15 minutes, then measure your blood sugar again. If it’s still low, repeat this process. If it’s normal, you can have a snack or a meal. Talk with your doctor about your strategy for safely increasing your blood sugar.
If you have very low blood sugar, you may need to be treated at a medical facility. You or someone with you should call 911 or your local emergency number.
Headache
Headache was a common side effect in studies of Janumet and Janumet XR. Headaches can be mild to severe. They can sometimes make it hard to concentrate or go about your normal routine.
It’s not known whether headaches are caused by Janumet. Changes in blood sugar can also cause them.
There are different types of headaches that have different symptoms. For example:
Tension headache symptoms include:
- stiff neck
- dull and aching pain
- pressure or tightness in the forehead
Cluster headaches have different symptoms, such as:
- pain on one side of the face
- pain behind an eye
Migraine headaches have severe symptoms that may need ongoing treatment. Symptoms include:
- pulsating feeling in your head
- nausea
- throbbing pain
- sensitivity to light
These are not complete lists of symptoms for various kinds of headache, but you can learn more here. Talk with your doctor if your headache doesn’t go away in a few days. If you have a sudden headache with extreme pain, it might be a medical emergency. If you feel it could be, call 911 or your local emergency number right away.
What might help
You can treat a mild headache with over-the-counter pain medication, such as ibuprofen or Tylenol. Lifestyle changes may also help prevent headaches. Be sure to drink enough water, get a good night’s sleep, exercise, and avoid consuming too much caffeine or alcohol. And if there are certain foods that trigger your headaches, avoid them.
If you have a headache that doesn’t go away in a few days or is very painful, talk with your doctor about possible treatments.
Bullous pemphigoid
Bullous pemphigoid is a rare immune system reaction that causes blisters on your skin. This is due to your immune system mistakenly attacking your healthy skin.
This reaction wasn’t reported in studies of Janumet or Janumet XR. But it was found in some people who took drugs in the same group as sitagliptin. Sitagliptin is one of the active ingredients in Janumet. (An active ingredient is what makes a drug work.)
Symptoms of bullous pemphigoid include blisters on the skin of your arms, legs, or lower belly.
What might help
If you develop skin blisters while taking Janumet or Janumet XR, call your doctor right away. If they confirm you have bullous pemphigoid, they’ll have you stop taking the drug. They may prescribe treatments to ease your skin symptoms. They may also prescribe a different treatment option for managing your blood sugar.
Allergic reaction
Like most drugs, Janumet and Janumet XR can cause allergic reaction in some people.
Symptoms can be mild to serious and include:
- skin rash
- itchiness
- flushing (temporary warmth, redness, or deepening of skin color)
- swelling under your skin, usually in your eyelids, lips, hands, or feet
- swelling of your mouth, tongue, or throat, which can make it hard to breathe
What might help
If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest an over-the-counter oral antihistamine, such as Benadryl (diphenhydramine), or a topical product, such as hydrocortisone cream, to manage your symptoms.
If your doctor confirms you’ve had a mild allergic reaction to Janumet or Janumet XR, they’ll decide if you should continue taking it.
If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.
If your doctor confirms you’ve had a serious allergic reaction to Janumet or Janumet XR, they may have you switch to a different treatment.
Keeping track of side effectsDuring your Janumet or Janumet XR treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking new drugs or using a combination of treatments.
Your side effect notes can include things such as:
- what dose of drug you were taking when you had the side effect
- how soon you had the side effect after starting that dose
- what your symptoms were
- how it affected your daily activities
- what other medications you were taking
- any other information you feel is important
Keeping notes and sharing them with your doctor will help them learn more about how Janumet or Janumet XR affects you. They can then use this information to adjust your treatment plan if needed.
Below are warnings to keep in mind before taking Janumet or Janumet XR.
Boxed warning: Risk of lactic acidosis
Janumet and Janumet XR have a
Lactic acidosis is when too much lactic acid builds up in your body. This condition could lead to death if it’s not treated.
To learn more, see the “Side effects explained” section above.
Other warnings
Janumet and Janumet XR may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before starting Janumet or Janumet XR. The list below includes factors to consider.
Low vitamin B12. Janumet and Janumet XR can cause a low level of vitamin B12. If you already have a low B12 level, you have an increased risk of this side effect. Your doctor can test your B12 to make sure it’s in the normal range. If it’s too low, you may be able to take a supplement.
Heart failure. Heart failure can get worse if you take Janumet or Janumet XR. If you already have heart failure, talk with your doctor about the risks and benefits of these drugs.
Liver problems. If you have liver damage, your risk of certain side effects may be higher. Your doctor may prescribe a different drug depending on your liver function.
Imaging tests. If you need to get an imaging test or scan done, it might include contrast dye. Contrast dye is injected into your vein to help doctors see images clearly and diagnose health problems. One type of contrast dye contains iodine. You may need to avoid Janumet and Janumet XR if you’re getting an imaging test with iodine contrast dye.
Upcoming surgery. If you have a surgical procedure coming up, your doctor may temporarily stop your Janumet or Janumet XR treatment. This is because some surgeries require you to eat less or no food for a certain amount of time beforehand. Since taking Janumet and eating less food can both lower your blood sugar, doing them together increases your risk of this condition.
Kidney problems. If you already have kidney damage, your risk of a serious side effect from Janumet or Janumet XR, such as lactic acidosis, may be higher. These drugs can also cause additional kidney damage as a side effect. If your kidney problems are severe, your doctor will likely not prescribe Janumet or Janumet XR. They’ll monitor your kidney function if you do take this drug.
Older adults. Some people who are ages 65 years or older have an increased risk of lactic acidosis. Talk with your doctor about your potential risk of this condition.
Hypoglycemia (low blood sugar). If you’re already taking a drug that lowers blood sugar, you may be at increased risk of low blood sugar. This is a side effect of Janumet and Janumet XR. Be sure to check your blood sugar levels while taking either of these drugs. And be aware of the symptoms of low blood sugar to watch for.
Allergic reaction. If you’ve had an allergic reaction to Janumet or Janumet XR, or any of their ingredients, your doctor will likely not prescribe either of them for you. Ask about other medications that might be better treatment options.
Alcohol and Janumet and Janumet XR
Be sure to avoid drinking large amounts of alcohol while taking Janumet or Janumet XR. Alcohol can cause hypoglycemia (low blood sugar), as can these medications. So your low blood sugar could be more severe if they’re taken together.
Alcohol use is also a risk factor for lactic acidosis, which is a rare but serious side effect of Janumet and Janumet XR. If you drink alcohol, talk with your doctor about limiting how much you drink while taking either of these medications.
Pregnancy and breastfeeding while taking Janumet or Janumet XR
It’s unclear whether taking Janumet or Janumet XR during pregnancy is safe. There isn’t enough research on their use during pregnancy to know the risks.
Talk with your doctor if you are pregnant or planning to become pregnant. They can discuss the risks and benefits with you.
If you take Janumet or Janumet XR during pregnancy, consider enrolling in a
There also haven’t been enough studies to know whether these drugs are safe for a breastfed infant. Talk with your doctor about the risks and benefits of this treatment if you’re breastfeeding. They can help you determine a healthy way to feed your child while you’re taking Janumet or Janumet XR.
Like most medications, Janumet and Janumet XR may cause mild or serious side effects. Most people who take Janumet or Janumet XR commonly have some mild side effects, especially right after starting treatment. Serious side effects are possible but aren’t common.
Be sure to ask your doctor any questions you have about Janumet or Janumet XR. Here are a few ideas to help get you started:
- Will my side effects be the same if I take Janumet instead of Janumet XR?
- How can I reduce my risk of lactic acidosis?
- Which blood tests do I need to monitor my kidney function during my treatment?
- How long will it take for my belly pain side effect to go away?
- Will a lower dose decrease my side effects?
For tips on managing your condition, sign up for Healthline’s type 2 diabetes newsletter. And if you’re looking to join a supportive group of people who share your condition, check out the Bezzy T2D online community.
Q:
I’m currently taking propranolol. Why does that make it hard to tell when I’m having side effects of hypoglycemia (low blood sugar)?
AnonymousA:
You can see when your blood sugar is low by measuring it with a glucometer, but your body will also show signs. These symptoms, which include a rapid heartbeat and sweating, let you know that you need to eat or drink something with sugar right away.
But propranolol makes your heart beat slower and stops you from sweating as much. So this drug hides two of your body’s signals that your blood sugar is too low. Other drugs in the same group as propranolol also hide these signs of low blood sugar. This group of drugs, called beta-blockers, are sometimes used to treat heart failure or high blood pressure.
This is not a reason to stop taking propranolol. Just be sure to check your blood sugar on a schedule. And talk with your doctor about ways to keep your blood sugar at a safe level throughout the day.
The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
