Compare metformin vs. Janumet

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Glucophage
(metformin)

Janumet
(sitagliptin / metformin)

Lowers blood sugar. Glucophage (metformin) is the first choice medicine to control your blood sugar and lower the risk of death from diabetes, although a few people may not tolerate the stomach side effects.Lowers your blood sugar. Janumet is a combination of two anti-diabetic medicines that work better together, but is available as brand only.
Reviews & ratings
Filter group. All currently selected
Filter group. All currently selected
5.01metformin
Reviews for metformin
65%
of people (All ages) say metformin is worth it
46%
say it works well
16%
say it's a big hassle
938 reviews
Have you used Glucophage (metformin)?
Worth itNot sureNot worth it
Reviews for Janumet
46%
+19% better vs. metformin
38%
+8% better vs. metformin
15%
-1% worse vs. metformin
Have you used Janumet (sitagliptin / metformin)?
Worth itNot sureNot worth it
Side effects
metforminJanumet
  • Diarrhea 41%
  • Nausea/vomiting 18%
  • Gas 6%
  • Weakness 3%
  • Indigestion 3%
  • Stomach pain 1%
  • Headache 1%
More metformin side effects »
  • Low blood sugar 15%
  • Diarrhea 4%
  • Ear, nose, or throat infection 1%
  • Headache 3%
More Janumet side effects »
How it works
metforminJanumet
Glucophage (metformin) is an anti-diabetic drug. It lowers the amount of sugar your body makes or absorbs, and allows your body use the existing insulin better.Janumet (sitagliptin / metformin) is a combination of two anti-diabetic medicines. Metformin lowers the amount of sugar your body produces, and sitagliptin enhances the release of insulin.
Type of medication
metforminJanumet
Prescription onlyPrescription only
Available as
metforminJanumet
  • Pill
  • Extended release pill
  • Liquid
  • Pill
  • Extended release
Used for
metforminJanumet
Risk factors for serious side effects
metforminJanumet
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Using contrast dye for procedures
  • Surgery
Detailed Glucophage (metformin) risks & warnings »
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Using contrast dye for procedures
  • Surgery
Detailed Janumet (sitagliptin / metformin) risks & warnings »
Pregnancy

Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

Alcohol
metforminJanumet
  • Limit or avoid alcohol when taking this medicine.
  • Excessive or chronic alcohol use can increase the risk of a dangerous side effect.
No alcohol related info.
Food
metforminJanumet
  • Always take it with food to lessen stomach upset.
  • Take with food to avoid upset stomach with diarrhea, nausea, and vomiting.
Kidneys and liver
metforminJanumet
  • Glucophage (metformin) can cause this rare life-threatening condition. Your doctor will check your kidneys and liver before you start. Symptoms include deep and rapid breathing, nausea, vomiting, and stomach pain. This is a medical emergency and you should get help right away. You're more likely to get this if you already have kidney problems. Glucophage (metformin) should be stopped 48 hours before and after surgery or any imaging procedure needing contrast dye.
  • Usually not a good choice for people with kidney problems. Your doctor will tell you if Glucophage (metformin) is right for you to take.
  • Not appropriate for those with poor kidney function.
Weight
metforminJanumet
  • Doesn't cause weight gain.
No weight related info.
Upsides and benefits
metforminJanumet
  • Improves sugar control and lowers A1c levels as much as 2%.
  • One of the few diabetes medicines that lowers the risk of death from diabetes-related complications.
  • Doesn't cause weight gain.
  • Rarely causes low blood sugar.
  • This 2-in-1 combination can lower the number of pills you have to take daily.
  • Lowers A1c (average blood sugar over time) up to 2.5%.
  • Available in extended and immediate release forms to allow better control of your blood sugar.
  • Doesn't increase your appetite unlike other anti-diabetic medicines.
  • Does not cause hypoglycemia or very low blood sugar.
Downsides and risks
metforminJanumet
  • Often causes stomach upset, like diarrhea, nausea, gas, or stomach cramping.
  • Usually not a good choice for people with kidney problems. Your doctor will tell you if Glucophage (metformin) is right for you to take.
  • Excessive or chronic alcohol use can increase the risk of a dangerous side effect.
  • Available as brand name only and may be expensive.
  • Metformin component usually causes upset stomach.
  • Sitagliptin component may increase your risk for throat infections and inflammation of pancreas.
  • Not appropriate for those with poor kidney function.
Tips from our pharmacists for people taking the medication
metforminJanumet
  • Can cause upset stomach with nausea and especially diarrhea in the first couple of weeks.
  • Always take it with food to lessen stomach upset.
  • Stay hydrated.
  • Limit or avoid alcohol when taking this medicine.
  • Tell your doctor about any deep or rapid breathing, or persistent nausea, vomiting, and stomach pain.
  • Check your blood sugar regularly.
  • Take with food to avoid upset stomach with diarrhea, nausea, and vomiting.
  • May cause headaches and cold-like symptoms.
  • Tell your doctor about any deep or rapid breathing, or persistent nausea, vomiting, and stomach pain.
  • Can be expensive depending on insurance coverage.
  • Check your blood sugar regularly.
Learn more
More about metforminSide effectsReviews & ratingsAlternativesFDA package insert
Have you used Glucophage (metformin)?
Worth itNot sureNot worth it
More about JanumetSide effectsReviews & ratingsAlternativesFDA package insert
Have you used Janumet (sitagliptin / metformin)?
Worth itNot sureNot worth it