Compare Metformin vs. Januvia

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

Glucophage
(Metformin)

Januvia
(Sitagliptin)

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. Januvia (Sitagliptin) is a good add-on treatment if your blood sugar is still too high, but you don't want to use an injectable medicine.
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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 Januvia (Sitagliptin)
44%
-21% worse vs. Glucophage (Metformin)
34%
-12% worse vs. Glucophage (Metformin)
17%
-1% worse vs. Glucophage (Metformin)
143 reviews
Have you used Januvia (Sitagliptin)?
Worth itNot sureNot worth it
Side effects
MetforminJanuvia
  • Diarrhea 41%
  • Nausea/vomiting 18%
  • Passing gas 6%
  • Muscle weakness 3%
  • Indigestion 3%
  • Abdominal discomfort 1%
  • Headache 1%
More Metformin side effects »
  • Common cold 2%
  • Diarrhea 1%
More Januvia side effects »
How it works
MetforminJanuvia
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.Januvia (Sitagliptin) is an anti-diabetic drug. It helps your body release more insulin in order to lower blood sugar.
Type of medication
MetforminJanuvia
Prescription only
Prescription only
Available as
MetforminJanuvia
  • Pill
  • Extended release
  • Liquid
  • Pill
Used for
MetforminJanuvia
Risk factors for serious side effects
MetforminJanuvia
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Using contrast dye for procedures
  • Surgery
  • Alcohol use
    Detailed Glucophage (Metformin) risks & warnings »
        Detailed Januvia (Sitagliptin) 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
        MetforminJanuvia
        • Always take it with food or switch to the extended release version to avoid upset stomach.
        No food related info.
        Kidneys and liver
        MetforminJanuvia
        • 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.
        No kidneys and liver related info.
        Weight
        MetforminJanuvia
        • Unlike some diabetes medicines, doesn't cause weight gain or low blood sugar.
        • Unlike some diabetes medicines, it's unlikely to cause weight gain and low blood sugar.
        Upsides and benefits
        MetforminJanuvia
        • 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.)
        • Prevents the harmful effects of high sugar levels on your organs and blood vessels.
        • Also lowers certain lipid (fat and cholesterol) levels.
        • Unlike some diabetes medicines, doesn't cause weight gain or low blood sugar.
        • You don't have to check your blood sugar every day with this medicine.
        • One of the least expensive diabetes medicines.
        • Oral blood sugar-lowering medicine.
        • Lowers A1c levels by 0.5-0.8%. (Hemoglobin A1c measures your average blood sugar over time.)
        • Prevents the harmful effects of high sugar levels on your organs and blood vessels.
        • Uses the hormones naturally produced by your body to affect how sugar is processed.
        • Unlike some diabetes medicines, it's unlikely to cause weight gain and low blood sugar.
        • You don't have to check your blood sugar every day with this medicine.
        Downsides and risks
        MetforminJanuvia
        • 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.
        • People with poor kidney function can't use it.
        • 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.
        • Not as strong as other diabetes medicines. Your doctor might add it to your blood sugar-lowering regimen if your sugar levels are still too high.
        • Likely expensive since there's no generic version available.
        • Some people might get frequent throat infections or nasal congestion.
        Tips from our pharmacists for people taking the medication
        MetforminJanuvia
        • 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.
        • Can cause headache and cold-like symptoms.
        • Tell your doctor about persistent stomach pain, nausea, vomiting, or loss of appetite.
        • 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 JanuviaSide effectsReviews & ratingsAlternativesFDA package insert
        Have you used Januvia (Sitagliptin)?
        Worth itNot sureNot worth it