Compare metformin vs. Human Insulin

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

Glucophage
(metformin)

Humulin
(human insulin)

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. This form of insulin is one of the few medications in its class that you can get without a prescription, but it's expensive.
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Reviews & ratings
Filter group. All currently selected
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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 Humulin (human insulin)
67%
+2% better vs. Glucophage (metformin)
46%
Same vs. Glucophage (metformin)
11%
+5% better vs. Glucophage (metformin)
Have you used Humulin (human insulin)?
Worth itNot sureNot worth it
Side effects
metforminHuman Insulin
  • Diarrhea 41%
  • Nausea/vomiting 18%
  • Gas 6%
  • Weakness 3%
  • Indigestion 3%
  • Stomach pain 1%
  • Headache 1%
More metformin side effects »

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

More about Human Insulin side effects »
How it works
metforminHuman Insulin
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.Insulin is a hormone normally produced by your pancreas. It helps your body absorb and store sugar and fat from your bloodstream.
Type of medication
metforminHuman Insulin
Prescription only
Prescription only
Available as
metforminHuman Insulin
  • Pill
  • Extended release pill
  • Liquid
  • Injection
  • Inhaler
Used for
metforminHuman Insulin
Risk factors for serious side effects
metforminHuman Insulin
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Using contrast dye for procedures
  • Surgery
Detailed Glucophage (metformin) risks & warnings »
    Detailed Humulin (human insulin) 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
    metforminHuman Insulin
    • 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
    metforminHuman Insulin
    • Always take it with food to lessen stomach upset.
    No food related info.
    Kidneys and liver
    metforminHuman Insulin
    • 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
    metforminHuman Insulin
    • Doesn't cause weight gain.
    • People on Humulin (Human Insulin) can experience weight gain. Talk to your doctor or dietitian about changing your diet if this bothers you.
    Upsides and benefits
    metforminHuman Insulin
    • 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.
    • Some types of this medication are available without a prescription.
    • Available as a shot to be injected into the fatty part of the skin, and as a powder to be inhaled through your nose.
    • Available in different combinations so that you can do one shot or multiple shots a day.
    Downsides and risks
    metforminHuman Insulin
    • 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.
    • Has to be taken exactly as directed or it can cause high or low blood sugar.
    • As with all insulins, you have to work with your doctor closely to make sure you're giving yourself the correct dose, or you can have low or high blood sugar.
    Tips from our pharmacists for people taking the medication
    metforminHuman Insulin
    • 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.
    • Change the location where you give yourself the shot every time.
    • Don't use if the liquid in the vial looks different than normal.
    • Store the unopened vials in the refrigerator. The used vials can be kept at room temperature for up to 28 days.
    • Take the medication exactly how your doctor tells you to.
    • Know the symptoms of low blood sugar.
    Learn more
    More about metforminSide effectsReviews & ratingsAlternativesFDA package insert
    Have you used Glucophage (metformin)?
    Worth itNot sureNot worth it
    More about Human InsulinSide effectsReviews & ratingsAlternativesFDA package insert
    Have you used Humulin (human insulin)?
    Worth itNot sureNot worth it