Key takeaways:
Janumet (sitagliptin / metformin) is a combination medication used to treat Type 2 diabetes in adults. Each pill contains two medications — sitagliptin and metformin. It can be a convenient option to help lower the number of pills you take per day.
A common starting Janumet dosage is 50 mg/500 mg by mouth twice daily with meals. Your dosage may be different if you were already taking metformin before starting Janumet. The maximum Janumet dosage is 50 mg/1,000 mg by mouth twice daily.
Janumet XR is a once-daily version of the medication. A common starting Janumet XR dosage is 100 mg/1,000 mg by mouth once daily with a meal. Your dosage may be different if you were already taking metformin before starting Janumet XR. The maximum dosage is 100 mg/2,000 mg by mouth once daily.
There are ways to save on Janumet and Janumet XR. If you’re eligible, a manufacturer savings card can help you get your prescription for as little as $5 per prescription. A patient assistance program is also available.
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If you’re living with Type 2 diabetes, there’s a good chance you’re taking metformin. It’s long been a first-choice treatment option to help lower blood glucose (sugar) levels. That’s because it’s one of the safest and most effective diabetes medications available.
But it’s common for people to need to take more than one medication in order to meet their diabetes treatment goals. One combination your prescriber may suggest is adding Januvia (sitagliptin) to your current metformin regimen. These two medications also come as a combination pill called Janumet (sitagliptin / metformin).
Taking a combination pill such as Janumet can be more convenient than taking each medication separately. But when you first start it, the way you take it may be different from what you’re used to. And this can cause some confusion until you settle into your new routine. If this sounds like you, we’ve got you covered. Below, we discuss typical Janumet dosages, plus what to do if you took too much.
What’s the typical Janumet dosage?
Usually, you take Janumet once or twice daily with meals. But your specific dosage depends on the formulation you’ve been prescribed. It also depends on whether you were already taking sitagliptin (Januvia’s active ingredient) or metformin as separate medications before starting.
Janumet comes as immediate-release (Janumet) and extended-release (Janumet XR) tablets. They come in the following doses (written as mg of sitagliptin / mg of metformin):
Janumet: 50 mg/500 mg, 50 mg/1,000 mg
Janumet XR: 50 mg/500mg, 50 mg/1,000 mg, 100 mg/1,000 mg
Don’t cut, chew, or crush Janumet or Janumet XR tablets. This can change how the medication is absorbed by your body.
Good to know: Janumet and Janumet XR are only FDA approved for use in adults age 18 and older. So this article doesn’t discuss dosages for children. Follow instructions from your child’s prescriber if they recommend this medication for them.
Janumet dosage
If you’ve never taken metformin, your starting Janumet dosage will likely be 50 mg/500 mg by mouth twice daily with meals. If you were already taking metformin, the amount of metformin in Janumet should be similar to what you were taking. If you were taking 850 mg of metformin twice daily, it’s recommended to start with Janumet 50 mg/1,000 mg twice daily.
Depending on how you tolerate Janumet, your prescriber may slowly raise your dosage. The maximum dosage is 50 mg/1,000 mg twice daily.
Janumet XR dosage
If you’ve never taken metformin, your starting Janumet XR dosage will likely be 100 mg/1,000 mg by mouth once daily with a meal. If you were already taking metformin, the amount of metformin in Janumet XR should be similar to what you were taking.
Some people may need to take two Janumet XR tablets per day to obtain a certain dose. In this case, you should take both tablets at the same time once daily. Don’t take Janumet XR twice daily. For instance, if you were taking 850 mg or 1,000 mg of immediate-release metformin twice daily, it’s recommended to start with two Janumet XR 50 mg/1,000 mg tablets once daily.
Depending on how you tolerate Janumet XR, your prescriber may slowly raise your dosage. The maximum dosage is 100 mg/2,000 mg once daily.
Two become one: Read about when and why combining sitagliptin (Januvia) and metformin can be beneficial.
Other combination pills: Janumet is one of several combination diabetes medications available. Learn more about some other options.
From plant to pill: Learn about metformin’s history and how it became a mainstay in the treatment of Type 2 diabetes.
Are there any dosage adjustments for health conditions?
If you have chronic kidney disease (CKD), you may need a lower Janumet XR dosage. But depending on how advanced your CKD is, you may not be able to take Janumet or Janumet XR.
The kidneys are responsible for clearing both sitagliptin and metformin from the body. If your kidneys aren’t working as expected, the medications in Janumet can build up in your body. This can raise your risk of side effects.
Your prescriber will use your estimated glomerular filtration rate (eGFR) to determine the best Janumet dosage for you. This is a blood test that can give healthcare professionals a snapshot of how your kidneys are functioning.
The manufacturer’s recommendations for Janumet and Janumet XR dosages based on eGFR can be found in the table below. But don’t try to adjust or stop the medication without your prescriber’s OK.
eGFR (written as mL/min/1.73m2) | Recommended Janumet dosage | Recommended Janumet XR dosage |
Greater than 45 | Follow typical Janumet dosage. | Follow typical Janumet XR dosage. |
30-45 | Janumet isn’t recommended. But you should still be able to take safe doses of Januvia and metformin separately at lower dosages. | Don’t start Janumet XR if you’re not already taking it. If you’re already taking Janumet XR, lower the total daily dose of sitagliptin component to 50 mg. Your prescriber may also suggest lowering your daily metformin dose. |
Below 30 | Janumet is contraindicated (not recommended because the risk of harm is too great). | Janumet is contraindicated. |
What happens if you miss a dose of Janumet?
If you miss your Janumet dose, take the medication as soon as possible. But if it’s almost time for your next dose, skip the missed one. Then take your next dose at its scheduled time. Don’t double up or take more than what’s been prescribed to try to correct missed doses.
Remembering to take your medication can be tricky. But there are ways to help keep you on track. Setting alarms, using a pill organizer, and downloading a medication reminder app on your smartphone are some things you can try.
What should you do if you take too much Janumet?
Taking an extra dose of Janumet by mistake is unlikely to cause serious harm. But you may experience more side effects, such as an upset stomach or diarrhea. You may also have a greater risk of hypoglycemia (low blood glucose).
Rarely, people who took too much metformin (or medications that contain it) experienced lactic acidosis. This is a life-threatening condition where there’s too much acid in the blood. Older adults, those with liver or kidney problems, and those who drink alcohol may have a higher risk of lactic acidosis after taking too much Janumet.
If you’ve taken too much Janumet, contact your prescriber or call Poison Control at 1-800-222-1222. If you notice severe symptoms, such as trouble breathing, seek immediate medical help by calling 911 or going to the nearest ER.
How to save on Janumet
There are ways to save on Janumet and Janumet XR, which are available as brand-name medications. GoodRx can help you navigate between patient assistance programs and copay savings cards to save money on your prescription.
Save with a copay savings card. If you have commercial insurance, you may be eligible to pay as little as $5 per prescription for Janumet and Janumet XR using a savings card from the manufacturer.
Save with patient assistance programs. If you’re uninsured or underinsured, you may be eligible for Janumet or Janumet XR’s patient assistance program, which offers the medication free of cost.
The bottom line
Janumet is a diabetes combination pill that contains sitagliptin and metformin. This medication comes in two forms: immediate-release (Janumet) and extended-release (Janumet XR) tablets.
A common starting Janumet dosage is 50 mg/500 mg by mouth twice daily with meals. A possible starting Janumet XR dosage is 100 mg/1,000 mg by mouth once daily with a meal. Your dosage may be different depending on whether you were already taking metformin before starting Janumet or Janumet XR.
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References
American Diabetes Association. (n.d.). Holistic person-centered approach to T2DM management.
American Diabetes Association Professional Practice Committee. (2023). 9. Pharmacologic approaches to glycemic treatment: Standards of care in diabetes—2024. Diabetes Care.
Merck Sharp & Dohme LLC. (2024). Janumet- sitagliptin and metformin hydrochloride tablet, film coated [package insert]. DailyMed.
Merck Sharp & Dohme LLC. (2024). Janumet XR- sitagliptin and metformin hydrochloride tablet, film coated, extended release [package insert]. DailyMed.
NKF Patient Education Team. (2022). Estimated glomerular filtration rate (eGFR). National Kidney Foundation.
