Compare metformin vs. Novolog

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

Glucophage
(metformin)

Novolog
(insulin aspart)

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. Novolog is a fast-acting insulin that provides meal-time sugar control. It can cause low blood sugar, so make sure you know what the symptoms are and always have a source of sugar nearby.
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Reviews & ratings
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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 Novolog (insulin aspart)
58%
-7% worse vs. Glucophage (metformin)
46%
Same vs. Glucophage (metformin)
19%
-3% worse vs. Glucophage (metformin)
177 reviews
Have you used Novolog (insulin aspart)?
Worth itNot sureNot worth it
Side effects
metforminNovolog
  • Diarrhea 41%
  • Nausea/vomiting 18%
  • Gas 6%
  • Weakness 3%
  • Indigestion 3%
  • Stomach pain 1%
  • Headache 1%
More metformin side effects »
  • Decreased muscle reflexes 11%
  • Nail fungal infection 10%
  • Abnormal sense of touch 9%
  • Urinary tract infection 8%
  • Chest pain 5%
  • Headache 5%
  • Skin disorder 5%
  • Abdominal pain 5%
  • Sinus inflammation 5%
  • Injury accidental 11%
More Novolog side effects »
How it works
metforminNovolog
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.Novolog is a short-acting insulin medicine for diabetes. It acts like the insulin that your body normally makes to process sugars and fats, and it keeps your blood sugar stable after meals.
Type of medication
metforminNovolog
Prescription only
Prescription only
Available as
metforminNovolog
  • Pill
  • Extended release pill
  • Liquid
  • Injection
Used for
metforminNovolog
Risk factors for serious side effects
metforminNovolog
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Using contrast dye for procedures
  • Surgery
  • Alcohol use
    Detailed Glucophage (metformin) risks & warnings »
    • Insulin dose too high
    • Use of other blood sugar lowering medicines
    • Poor injection techniques
    • Unstable kidney functions
    • Unstable liver functions
    • Use of other medicine that lowers potassium
    • Current electrolyte imbalance
      Detailed Novolog (insulin aspart) 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
      metforminNovolog
      • 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
      metforminNovolog
      • Always take it with food to lessen stomach upset.
      • Novolog is a fast-acting insulin that provides sugar control after meals.
      • Short-acting insulin good for blood sugar control around meal times.
      Kidneys and liver
      metforminNovolog
      • 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.
      • Okay to use even if you have liver or kidney problems, unlike most other blood sugar-lowering medicines.
      Weight
      metforminNovolog
      • Doesn't cause weight gain.
      • Likely to cause moderate weight gain (around 4 to 6 pounds).
      • Can cause weight gain and low blood sugar.
      Upsides and benefits
      metforminNovolog
      • 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.
      • Insulin is the most effective blood sugar-lowering medicine. When used correctly, it'll lower blood sugar every time you use it and prevent the harmful effects of high sugar levels on your organs and blood vessels.
      • Novolog is a fast-acting insulin that provides sugar control after meals.
      • Dose can be easily adjusted to make a customized regimen that's tailored to your body.
      • Starting insulin early in the treatment of Type 2 diabetes can maintain your body's insulin-producing cells and slow down disease progression.
      • Okay to use even if you have liver or kidney problems, unlike most other blood sugar-lowering medicines.
      Downsides and risks
      metforminNovolog
      • 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.
      • You have to take insulin by injection.
      • You have to check your blood sugar multiple times every day, usually before each meal.
      • Likely to cause moderate weight gain (around 4 to 6 pounds).
      • Higher risk of low blood sugar episodes than other kinds of diabetes medicines.
      Tips from our pharmacists for people taking the medication
      metforminNovolog
      • 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.
      • Short-acting insulin good for blood sugar control around meal times.
      • Take 5 to 10 minutes before a meal. Effects last for 2-4 hours.
      • Can cause weight gain and low blood sugar.
      • Make sure you and your family know the symptoms of low blood sugar: sweating, shakiness, weakness, fast heartbeat, nervousness, headache, blurry vision, trouble thinking clearly, or passing out.
      • Always have a good source of sugar nearby for low blood sugar episodes.
      • Make sure you understand how to give yourself the injections.
      • When mixing with another insulin (such as insulin NPH), draw this insulin into the syringe first.
      • Don't shake the vial. Store unopened vials in the refrigerator. Opened vials are good at room temperature for 28 days.
      • Check your blood sugar levels every day.
      Learn more
      More about metforminSide effectsReviews & ratingsAlternativesFDA package insert
      Have you used Glucophage (metformin)?
      Worth itNot sureNot worth it
      More about NovologSide effectsReviews & ratingsAlternativesFDA package insert
      Have you used Novolog (insulin aspart)?
      Worth itNot sureNot worth it