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 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. 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
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 Novolog (Insulin Aspart)
58%
7% vs. Glucophage (Metformin)
46%
Same vs. Glucophage (Metformin)
18%
2% vs. Glucophage (Metformin)
Side effects
MetforminNovolog
  • Diarrhea 41%
  • Nausea/vomiting 18%
  • Passing gas 6%
  • Indigestion 3%
  • Muscle weakness 3%
  • Abdominal discomfort 1%
  • Headache 1%
More Metformin side effects »

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

More about Novolog side effects »
How it works
MetforminNovolog
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.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
Anti-diabetic
Biguanide
Prescription only
Anti-diabetic
Insulin
Prescription only
Available as
MetforminNovolog
  • Pill
  • Extended release
  • Liquid
  • Injection
Used for (click to learn more)
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 category
      MetforminNovolog
      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.
      • You have to check your blood sugar multiple times every day, usually before each meal.
      • Novolog is a fast-acting insulin that provides sugar control after meals.
      • 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.
      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.
      • Okay to use even if you have liver or kidney problems, unlike most other blood sugar-lowering medicines.
      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.
      • Likely to cause moderate weight gain (around 4 to 6 pounds).
      • Can cause weight gain and low blood sugar.
      Upsides and benefits
      MetforminNovolog
      • 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.
      • 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
      • 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.
      • 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 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.
      • 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
      More about NovologSide effectsReviews & ratingsAlternativesFDA package insert