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 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 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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Coupons for metformin
Best available price for 60 (500mg) tablets of metformin
Coupons for Januvia
Best available price for 30 (100mg) tablets of sitagliptin
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%
  • Gas 6%
  • Weakness 3%
  • Indigestion 3%
  • Stomach pain 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 the amount of sugar your body makes or absorbs, and allows your body use the existing insulin better.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 pill
  • 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
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.

    Alcohol
    metforminJanuvia
    • Excessive or chronic alcohol use can increase the risk of a dangerous side effect.
    • Limit or avoid alcohol when taking this medicine.
    No alcohol related info.
    Food
    metforminJanuvia
    • Always take it with food to lessen stomach upset.
    No food related info.
    Kidneys and liver
    metforminJanuvia
    • Usually not a good choice for people with kidney problems. Your doctor will tell you if Glucophage (metformin) is right for you to take.
    • 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.
    No kidneys and liver related info.
    Weight
    metforminJanuvia
    • Doesn't cause weight gain.
    • Unlike some diabetes medicines, it's unlikely to cause weight gain and low blood sugar.
    Upsides and benefits
    metforminJanuvia
    • 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.
    • 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
    • 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.
    • 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 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.
    • 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