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 a very effective medicine to lower blood sugar and the risk of complications and death from diabetes, but it's likely to cause diarrhea for the first few weeks.Lowers blood sugar. Janumet is an expensive but very effective combination of oral blood sugar-lowering medicines.
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Reviews & ratings
Filter group. All currently selected
Filter group. All currently selected
5.01Metformin
Reviews for Glucophage (Metformin)
65%
of people (All ages) say Glucophage (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 (Sitagliptin / Metformin)
46%
19% vs. Glucophage (Metformin)
38%
8% vs. Glucophage (Metformin)
15%
+1% vs. Glucophage (Metformin)
Have you used Janumet (Sitagliptin / Metformin)?
Worth itNot sureNot worth it
Side effects
MetforminJanumet

The Metformin FDA package insert doesn’t have numbers about how common side effects are.

More about Metformin side effects »

The Janumet FDA package insert doesn’t have numbers about how common side effects are.

More about Janumet side effects »
How it works
MetforminJanumet
Glucophage (Metformin) is an anti-diabetic drug. It lowers sugar production in your body, decreases sugar absorption in your intestines, and makes your body more sensitive to insulin.Janumet is an antidiabetic combination medicine. Metformin lowers the amount of sugar your body produces, and sitagliptin helps your body release more insulin.
Type of medication
MetforminJanumet
Anti-diabetic
Biguanide
Prescription only
Anti-diabetic
DPP-4 inhibitor
Biguanide
Prescription only
Available as
MetforminJanumet
  • Pill
  • Extended release
  • Liquid
  • Pill
  • Extended release
Used for (click to learn more)
MetforminJanumet
Risk factors for serious side effects
MetforminJanumet
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Using contrast dye for procedures
  • Surgery
Detailed risks & warnings »
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Contrast dye for procedure
  • Surgery
Detailed 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.

Food
MetforminJanumet
  • Always take it with food or switch to the extended release version to avoid upset stomach.
  • Take it with food to avoid upset stomach with diarrhea, nausea, and vomiting.
Kidneys and liver
MetforminJanumet
  • People with poor kidney function can't use it.
  • Glucophage (Metformin) can cause this rare but life-threatening condition. Symptoms include deep and rapid breathing, nausea, vomiting, and stomach pain. This is a medical emergency and you should get help right away. Baseline blood work for kidney and liver function are helpful to see if you can use Glucophage (Metformin). It may not be a good choice for people with kidney problems. Glucophage (Metformin) should be stopped 48 hours before and/or after surgery or any imaging procedure needing contrast dye.
  • People with poor kidney function can't use it.
  • Janumet (Sitagliptin / Metformin) can cause this rare but life-threatening condition. Symptoms include deep and rapid breathing, nausea, vomiting, and stomach pain. This is a medical emergency and you should get help right away. Baseline blood work for kidney and liver function are helpful to see if you can use Janumet (Sitagliptin / Metformin). It may not be a good choice for people with kidney problems. Janumet (Sitagliptin / Metformin) should be stopped 48 hours before and/or after surgery or any imaging procedure needing contrast dye.
Weight
MetforminJanumet
  • Unlike some diabetes medicines, doesn't cause weight gain or low blood sugar.
  • Doesn't cause weight gain or low blood sugar.
Upsides and benefits
MetforminJanumet
  • Oral blood sugar-lowering medicine.
  • A common first treatment for people with newly-diagnosed Type 2 diabetes.
  • The only oral diabetes medicine that lowers complications and deaths from conditions related to diabetes.
  • Lowers A1c levels by 1-2%. (Hemoglobin A1c measures your average blood sugar over time.)
  • Also lowers certain lipid (fat and cholesterol) levels.
  • Unlike some diabetes medicines, doesn't cause weight gain or low blood sugar.
  • One of the least expensive diabetes medicines.
  • Prevents the harmful effects of high sugar levels on your organs and blood vessels.
  • You don't have to check your blood sugar every day with this medicine.
  • 2-in-1 combination medicine. If you need more than one blood sugar medicine, this lowers the number of pills you have to take.
  • Lowers A1c levels by 1-2.5%. (Hemoglobin A1c measures your average blood sugar over time.)
  • Doesn't cause weight gain or low blood sugar.
  • Prevents the harmful effects of high sugar levels on your organs and blood vessels.
  • You don't have to check your blood sugar every day with this medicine.
Downsides and risks
MetforminJanumet
  • Most people will have nausea, indigestion, or diarrhea in the first few weeks. You can minimize this if you take it on a full stomach.
  • Only works if your body can still make your own insulin, a hormone that tells your body what to do with sugar, protein, and fat.
  • People with poor kidney function can't use it.
  • Likely expensive since there's no generic version available.
  • The metformin part of Janumet can cause nausea, indigestion, or diarrhea for most people in the first few weeks.
  • The sitagliptin part of Janumet can cause some people to have frequent throat infections or nasal congestion.
  • Might raise the risk of problems with your pancreas.
  • People with poor kidney function can't use it.
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 or switch to the extended release version to avoid upset stomach.
  • Tell your doctor about any deep or rapid breathing, or persistent nausea, vomiting, and stomach pain.
  • Check your blood sugar regularly.
  • Take it with food to avoid upset stomach with diarrhea, nausea, and vomiting.
  • May cause headaches and cold-like symptoms.
  • Can be expensive depending on insurance coverage.
  • Tell your doctor about any deep or rapid breathing, or persistent nausea, vomiting, and stomach pain.
  • 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