Compare Metformin vs. Actos

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

Glucophage
(Metformin)

Actos
(Pioglitazone)

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. Actos (Pioglitazone) is a last-choice blood sugar-lowering medicine since it's only moderately effective but has a lot of undesirable side effects.
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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 Actos (Pioglitazone)
42%
23% vs. Glucophage (Metformin)
30%
16% vs. Glucophage (Metformin)
21%
5% vs. Glucophage (Metformin)
175 reviews
Have you used Actos (Pioglitazone)?
Worth itNot sureNot worth it
Side effects
MetforminActos

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

More about Metformin side effects »
  • Swelling due to excess fluid 6%
More Actos side effects »
How it works
MetforminActos
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.Actos (Pioglitazone) is an anti-diabetic drug. It improves your body's ability to use insulin to lower your blood sugar.
Type of medication
MetforminActos
Anti-diabetic
Biguanide
Prescription only
Anti-diabetic
Thiazoladinedione
Prescription only
Available as
MetforminActos
  • Pill
  • Extended release
  • Liquid
  • Pill
Used for (click to learn more)
MetforminActos
Risk factors for serious side effects
MetforminActos
  • Kidney problems
  • Liver problems
  • Congestive heart failure
  • Using contrast dye for procedures
  • Surgery
Detailed risks & warnings »
  • Heart failure diagnosis
  • Current liver problems
  • Female
Detailed 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 found harmful effects on unborn babies. It hasn’t been properly studied in humans. The benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

Food
MetforminActos
  • Always take it with food or switch to the extended release version to avoid upset stomach.
No food related info.
Kidneys and liver
MetforminActos
  • 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 kidneys and liver related info.
Weight
MetforminActos
  • Unlike some diabetes medicines, doesn't cause weight gain or low blood sugar.
  • More likely to cause weight gain (2 to 6 pounds or more) compared to other blood sugar-lowering medicines.
  • Can cause weight gain, headache, and fluid retention.
Upsides and benefits
MetforminActos
  • 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.)
  • 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.
  • Oral blood sugar-lowering medicine.
  • Prevents the harmful effects of high sugar levels on your organs and blood vessels.
  • Lowers A1c levels by around 1%. (Hemoglobin A1c measures your average blood sugar over time.)
  • Rarely causes low blood sugar.
  • Oral blood sugar-lowering medicine.
  • Prevents the harmful effects of high sugar levels on your organs and blood vessels.
Downsides and risks
MetforminActos
  • 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.
  • May take several weeks to lower blood sugar.
  • You have to check your blood sugar regularly with this medicine.
  • Has more side effects than similar medicines, so it's usually not the first choice for new Type 2 diabetes patients.
  • More likely to cause weight gain (2 to 6 pounds or more) compared to other blood sugar-lowering medicines.
  • Up to 1 in 10 people might get fluid retention (edema), ranging from mild ankle swelling to severe swelling in the lungs that makes it hard to breathe. People with severe congestive heart failure shouldn't use Actos.
  • Raises the risk of bone fractures, especially for people who already have a risk for fractures.
  • Slightly raises the risk of bladder cancer.
Tips from our pharmacists for people taking the medication
MetforminActos
  • 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.
  • Takes several weeks to see full effect on blood sugar control.
  • Can cause weight gain, headache, and fluid retention.
  • Tell your doctor about any mental confusion, persistent abdominal pain, dark urine, yellowing of eyes/skin, or easy bruising.
  • Not recommended for patients with certain heart problems.
  • 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 ActosSide effectsReviews & ratingsAlternativesFDA package insert
Have you used Actos (Pioglitazone)?
Worth itNot sureNot worth it