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 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. 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
Button Group. All currently active
Button Group. All currently active
5.008611410118407Metformin
Reviews for Glucophage (Metformin)
65%
of people say Glucophage (Metformin) is worth it
46%
say it works well
16%
say it's a big hassle
Reviews for Humulin (Human Insulin)
67%
+2% vs. Glucophage (Metformin)
46%
Same vs. Glucophage (Metformin)
11%
+5% vs. Glucophage (Metformin)
Side effects
MetforminHuman insulin
  • Diarrhea 41%
  • Nausea/vomiting 18%
  • Passing gas 6%
  • Indigestion 3%
  • Muscle weakness 3%
  • Abdominal discomfort 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 sugar production in your body, decreases sugar absorption in your intestines, and makes your body more sensitive to insulin.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
Anti-diabetic
Biguanide
Prescription only
Anti-diabetic
Insulin
Prescription only
Available as
MetforminHuman insulin
  • Pill
  • Extended release
  • Liquid
  • Injection
  • Inhaler
Used for (click to learn more)
MetforminHuman insulin
Risk factors for serious side effects
MetforminHuman insulin
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Using contrast dye for procedures
  • Surgery
  • Alcohol use
    Detailed Glucophage (Metformin) risks & warnings »
          Detailed Humulin (Human Insulin) risks & warnings »
          Pregnancy category
          MetforminHuman insulin
          BFDA pregnancy category (Probably safe)

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

          See the FDA package insert
          BFDA pregnancy category (Probably safe)

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

          See the FDA package insert
          Alcohol
          No specific alcohol-related info.No specific alcohol-related info.
          Food
          • Always take it with food or switch to the extended release version to avoid upset stomach.
          No specific food-related info.
          Kidneys and liver
          • 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 specific kidneys and liver-related info.
          Sex
          No specific sex-related info.No specific sex-related info.
          Sleep
          No specific sleep-related info.No specific sleep-related info.
          Weight
          • Unlike some diabetes medicines, doesn't cause weight gain or low blood sugar.
          • 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
          • 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.
          • 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
          • 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.
          • 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 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.
          • 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
          More about Human insulinSide effectsReviews & ratingsAlternativesFDA package insert