Table of ContentsView AllTable of ContentsTreating DiabetesHow It WorksUsesSide EffectsTaking MetforminInteractionsFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Treating Diabetes
How It Works
Uses
Side Effects
Taking Metformin
Interactions
Frequently Asked Questions
To lessen the impact type 2 diabetes may have on your or a loved one’s quality of life, you may turn to a prescription drug regimen to controlhigh blood sugar (glucose)levels.
As such, your healthcare provider may recommend metformin, a prescription drug used to treattype 2 diabetes. It’s an oral medication that comes in several brand-name and generic versions. Metformin comes in immediate-release (IR) and extended-release (ER) forms.
Metformin is prescribed to manage high blood sugar levels in people with type 2 diabetes.Healthcare providers prescribe it alone or with other diabetes drugs. It’s typicallythe first medication a healthcare provider prescribesif they diagnose the condition.
Keep reading this article to learn more about metformin, how it works, its side effects, dosage, and what to expect if your healthcare provider prescribes metformin.
Getty Images / Tom Kelley
Type 2 diabetes is a chronic condition affecting the body’s ability to metabolize sugar (glucose), leading to hyperglycemia (high levels of glucose in the blood).
Usually, when your blood glucose rises, the body releases the natural hormoneinsulinto help your body lower it. Insulin facilitates the movement of sugar into cells, where your body can process it into energy.
However, in people with type 2 diabetes, the body either doesn’t make enough insulin or has developedinsulin resistance. This means your body is no longer sensitive or responsive to insulin release. As a result, your blood sugar levels increase.
Over time, high blood sugar causes damage to the body and can lead to severe complications, such as heart disease, vision loss, and kidney problems.
How Does Metformin Work?
The Food and Drug Administration (FDA) approves metformin to improve blood glucose levels in people with type 2 diabetes.
The drug is used in addition todiet and exercisein adults and children 10 and older with type 2 diabetes. Metformin belongs to thebiguanideclass of medications.
When cells take in more glucose, your blood sugar level decreases. In people with type 2 diabetes, the pancreas usually doesn’t produce enough insulin to meet the demand.
Glucosecomes from the food that you eat and is used to produce energy. If you consume more glucose than your body needs for fueling your activities, the extra glucose is kept “in storage” in your liver asglycogen.
When the liver breaks down glycogen, it releases glucose into the body, increasing blood sugar levels. This leads to your body becoming less sensitive to insulin (known as insulin resistance).
When to Use Metformin
Metformin is a first-line treatment for people with type 2 diabetes. The American Diabetes Association (ADA) recommends metformin, and lifestyle changes, like diet and exercise, as the first intervention in treating type 2 diabetes.
Metformin is highly effective, safe, inexpensive and may reduce the risk of severe complications and death.Metformin is an oral medication conveniently easier to administer than injectable diabetes drugs.
This drug commonly causesstomach upset, such as loose bowel movements, especially when you start taking it. Gradual dose increases, and taking each dose with food helps to minimize these side effects.
It should not be used in people with specific health problems, including severekidney impairmentor metabolic acidosis.
Doing so increases the risk of a severe condition calledlactic acidosis (a painful medical condition that can result in serious heart problems), includingdiabetic ketoacidosis.
Metformin is not used to treat type 1 diabetes. A healthcare provider can help determine if metformin might be suitable for you.
How Long Does Metformin Last?
Metformin IR takes about four days to get out of your system.
Comparatively, metformin ER provided greater blood glucose control and caused less digestive upset than IR metformin.
For context, ER medications gradually release a certain amount of the active drug over time, helping maintain more steady levels of the medicines in your body.
Regardless, the time metformin lasts in the body directly correlates with your specific diagnosis and dosage.
Side Effects & Safety
Metformin carries a boxed warning from the FDA cautioning against metformin use in instances of severe kidney impairment or metabolic acidosis.
Read below for specific side effects metformin has the potential to cause.
Common Side Effects
The most common side effects of metformin are digestive upset, such asdiarrhea,nausea,vomiting,gas, andindigestion.
You can take metformin with a meal or snack to help lessen these side effects. Your healthcare provider will also start you with a low dose and increase it over a few days or weeks.
This approach also helps to minimize gastrointestinal (GI) side effects. Digestive side effects of metformin usually go away after a few days of consistent use.
Other possible side effects of metformin includemuscle weakness,headache, andhypoglycemia(when blood sugar levels fall too low).
Is Weight Loss a Side Effect of Metformin?
Severe Side Effects
Severe: Metformin carries a boxed warning for the risk of lactic acidosis. The risk of lactic acidosis is higher in people with severekidney impairment.
Long-term: Though metformin is a relatively safe medication, using metformin long-term can affectvitamin B12 levels. Metformin can decrease the amount of B12 absorbed in the body.
Low vitamin B12 can lead toanemiaandiron deficiency.
Your healthcare provider may monitor your B12 level using blood tests from time to time while you’re taking the medication.
You should not take metformin if you have the following:
Be sure to discuss all of your medical conditions with your healthcare provider before starting metformin.
If you think metformin might be a good option, speak to a healthcare provider. Discuss your medical history, allergies, and all current medications, including prescription, over-the-counter (OTC) drugs, and supplements, with them.Sharing this information will help your healthcare provider determine if metformin is safe.
If you think metformin might be a good option, speak to a healthcare provider. Discuss your medical history, allergies, and all current medications, including prescription, over-the-counter (OTC) drugs, and supplements, with them.
Sharing this information will help your healthcare provider determine if metformin is safe.
How to Take Metformin
The usual starting dosage of metformin IR tablets in adults is 500 milligrams (mg) to 850 mg, taken once or twice daily with food.
Your healthcare provider may gradually increase your dose over time. The maximum dosage is 2,000-2,250 mg per day. It is usually divided into three doses, one with each meal.
The usual starting dosage of metformin IR tablet in children is 500 mg, taken once or twice daily with food. The maximum dosage in children is 2,000 mg per day. This is usually divided into two or three doses with food throughout the day.
The usual starting dosage of metformin ER in adults is 500 mg, taken once daily with the evening meal. Your healthcare provider may gradually increase your dose over time. The maximum amount is 2,000 mg per day taken with the evening meal. You should not crush, cut, or chew metformin ER tablets.
Your healthcare provider may prescribe a lower metformin dosage depending on your kidney function. Also, you may have to pause taking metformin in preparation for specific medical procedures. A healthcare provider can tell you more about this.
Your healthcare provider will monitor yourblood sugarand adjust your dose of metformin accordingly. You can also check your blood sugar levels at home.
In many cases, metformin may not be enough to bring your blood sugar levels within your goal range. Your healthcare provider may prescribe additional diabetesmedicationsto help control your blood sugar.
Ozempic vs. Metformin: What’s the Difference?
Metformin Interactions
Interactions may occur with metformin. Some drug interactions can be dangerous, while others are unlikely to have consequences.
Your healthcare provider can help you avoid or manage interactions. Before taking metformin, talk with your provider about all your current medications, including OTC and supplements.
Interactions with metformin may include:
Before starting metformin, talk to your healthcare provider to determine if you should avoid or limit alcohol use while taking this medication.
Summary
Metformin is an effective and commonly administered drug for treating type 2 diabetes.
Talk to a healthcare provider if you have questions about taking metformin.
Rybelsus vs. Metformin: Similarities and Differences
Frequently Asked QuestionsYes.Diet and exercisechanges can tremendously impact diabetes and your overall health.Studies have shown an association between weight loss from healthy lifestyle changes and remission of type 2 diabetes—potentially reversing the condition.The ADA recommends that people with diabetes get at least 150 minutes of moderate-intensity exercise weekly.The original brand name of metformin was Glucophage, but it was discontinued. Available brand versions of metformin include Glumetza and Fortamet.Metformin is also an active ingredient in many combination drugs for diabetes. Combination drugs offer the convenience of two medications in one pill. Examples include:Actoplus Met (metformin and pioglitazone), Invokamet (metformin and canagliflozin), Segluroment (metformin and ertugliflozin), and Synjardy (metformin and empagliflozin).
Yes.Diet and exercisechanges can tremendously impact diabetes and your overall health.Studies have shown an association between weight loss from healthy lifestyle changes and remission of type 2 diabetes—potentially reversing the condition.The ADA recommends that people with diabetes get at least 150 minutes of moderate-intensity exercise weekly.
Yes.Diet and exercisechanges can tremendously impact diabetes and your overall health.
Studies have shown an association between weight loss from healthy lifestyle changes and remission of type 2 diabetes—potentially reversing the condition.
The ADA recommends that people with diabetes get at least 150 minutes of moderate-intensity exercise weekly.
The original brand name of metformin was Glucophage, but it was discontinued. Available brand versions of metformin include Glumetza and Fortamet.Metformin is also an active ingredient in many combination drugs for diabetes. Combination drugs offer the convenience of two medications in one pill. Examples include:Actoplus Met (metformin and pioglitazone), Invokamet (metformin and canagliflozin), Segluroment (metformin and ertugliflozin), and Synjardy (metformin and empagliflozin).
The original brand name of metformin was Glucophage, but it was discontinued. Available brand versions of metformin include Glumetza and Fortamet.
Metformin is also an active ingredient in many combination drugs for diabetes. Combination drugs offer the convenience of two medications in one pill. Examples include:Actoplus Met (metformin and pioglitazone), Invokamet (metformin and canagliflozin), Segluroment (metformin and ertugliflozin), and Synjardy (metformin and empagliflozin).
20 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Metformin.DailyMed.Label: Metformin hydrochloride- metformin hydrochloride extended-release tablets tablet, film coated, extended release.American Diabetes Association Professional Practice Committee.9. Pharmacologic approaches to glycemic treatment: Standards of medical care in diabetes—2022.Diabetes Care. 2022;45:S125-S143. doi:10.2337/dc22-S009Rena G, Hardie DG, Pearson ER.The mechanisms of action of metformin.Diabetologia. 2017;60(9):1577-1585. doi:10.1007/s00125-017-4342-zMedlinePlus.Type 2 diabetes.Centers for Disease Control and Prevention.About insulin resistance and type 2 diabetes.Centers for Disease Control and Prevention.About type 2 diabetes.Food and Drug Administration.FDA drug safety communication: FDA revises warnings regarding use of the diabetes medicine metformin in certain patients with reduced kidney function.MedlinePlus.Diabetes medicines.American Diabetes Association.Diabetes and high blood pressure.MedlinePlus.Blood glucose.Adeva-Andany MM, Pérez-Felpete N, Fernández-Fernández C, Donapetry-García C, Pazos-García C.Liver glucose metabolism in humans.Bioscience Reports. 2016;36(6):e00416. doi:10.1042/BSR20160385Holman RR, Paul SK, Bethel MA, Matthews DR, Neil HAW.10-year follow-up of intensive glucose control in type 2 diabetes.N Engl J Med. 2008;359:1577–1589. doi:10.1056/NEJMoa0806470DailyMed. National Institutes of Health.Metformin hydrochloride tablet, film coated.Derosa G, D’Angelo A, Romano D, Maffioli P.Effects of metformin extended release compared to immediate release formula on glycemic control and glycemic variability in patients with type 2 diabetes.Drug Des Devel Ther.2017;11:1481-1488. doi:10.2147%2FDDDT.S131670National Heart, Lung, and Blood Institute.Vitamin B12-deficiency anemia.de Jager J, Kooy A, Lehert P, et al.Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: Randomised placebo controlled trial.BMJ. 2010;340:c2181. doi:10.1136/bmj.c2181Prescribers' Digital Reference.Metformin hydrochloride - drug summary.Dambha-Miller H, Day AJ, Strelitz J, Irving G, Griffin SJ.Behaviour change, weight loss and remission of type 2 diabetes: a community-based prospective cohort study.Diabet Med.2020;37(4):681-688. doi:10.1111/dme.14122American Diabetes Association.Eating well with diabetes.
20 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Metformin.DailyMed.Label: Metformin hydrochloride- metformin hydrochloride extended-release tablets tablet, film coated, extended release.American Diabetes Association Professional Practice Committee.9. Pharmacologic approaches to glycemic treatment: Standards of medical care in diabetes—2022.Diabetes Care. 2022;45:S125-S143. doi:10.2337/dc22-S009Rena G, Hardie DG, Pearson ER.The mechanisms of action of metformin.Diabetologia. 2017;60(9):1577-1585. doi:10.1007/s00125-017-4342-zMedlinePlus.Type 2 diabetes.Centers for Disease Control and Prevention.About insulin resistance and type 2 diabetes.Centers for Disease Control and Prevention.About type 2 diabetes.Food and Drug Administration.FDA drug safety communication: FDA revises warnings regarding use of the diabetes medicine metformin in certain patients with reduced kidney function.MedlinePlus.Diabetes medicines.American Diabetes Association.Diabetes and high blood pressure.MedlinePlus.Blood glucose.Adeva-Andany MM, Pérez-Felpete N, Fernández-Fernández C, Donapetry-García C, Pazos-García C.Liver glucose metabolism in humans.Bioscience Reports. 2016;36(6):e00416. doi:10.1042/BSR20160385Holman RR, Paul SK, Bethel MA, Matthews DR, Neil HAW.10-year follow-up of intensive glucose control in type 2 diabetes.N Engl J Med. 2008;359:1577–1589. doi:10.1056/NEJMoa0806470DailyMed. National Institutes of Health.Metformin hydrochloride tablet, film coated.Derosa G, D’Angelo A, Romano D, Maffioli P.Effects of metformin extended release compared to immediate release formula on glycemic control and glycemic variability in patients with type 2 diabetes.Drug Des Devel Ther.2017;11:1481-1488. doi:10.2147%2FDDDT.S131670National Heart, Lung, and Blood Institute.Vitamin B12-deficiency anemia.de Jager J, Kooy A, Lehert P, et al.Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: Randomised placebo controlled trial.BMJ. 2010;340:c2181. doi:10.1136/bmj.c2181Prescribers' Digital Reference.Metformin hydrochloride - drug summary.Dambha-Miller H, Day AJ, Strelitz J, Irving G, Griffin SJ.Behaviour change, weight loss and remission of type 2 diabetes: a community-based prospective cohort study.Diabet Med.2020;37(4):681-688. doi:10.1111/dme.14122American Diabetes Association.Eating well with diabetes.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
MedlinePlus.Metformin.DailyMed.Label: Metformin hydrochloride- metformin hydrochloride extended-release tablets tablet, film coated, extended release.American Diabetes Association Professional Practice Committee.9. Pharmacologic approaches to glycemic treatment: Standards of medical care in diabetes—2022.Diabetes Care. 2022;45:S125-S143. doi:10.2337/dc22-S009Rena G, Hardie DG, Pearson ER.The mechanisms of action of metformin.Diabetologia. 2017;60(9):1577-1585. doi:10.1007/s00125-017-4342-zMedlinePlus.Type 2 diabetes.Centers for Disease Control and Prevention.About insulin resistance and type 2 diabetes.Centers for Disease Control and Prevention.About type 2 diabetes.Food and Drug Administration.FDA drug safety communication: FDA revises warnings regarding use of the diabetes medicine metformin in certain patients with reduced kidney function.MedlinePlus.Diabetes medicines.American Diabetes Association.Diabetes and high blood pressure.MedlinePlus.Blood glucose.Adeva-Andany MM, Pérez-Felpete N, Fernández-Fernández C, Donapetry-García C, Pazos-García C.Liver glucose metabolism in humans.Bioscience Reports. 2016;36(6):e00416. doi:10.1042/BSR20160385Holman RR, Paul SK, Bethel MA, Matthews DR, Neil HAW.10-year follow-up of intensive glucose control in type 2 diabetes.N Engl J Med. 2008;359:1577–1589. doi:10.1056/NEJMoa0806470DailyMed. National Institutes of Health.Metformin hydrochloride tablet, film coated.Derosa G, D’Angelo A, Romano D, Maffioli P.Effects of metformin extended release compared to immediate release formula on glycemic control and glycemic variability in patients with type 2 diabetes.Drug Des Devel Ther.2017;11:1481-1488. doi:10.2147%2FDDDT.S131670National Heart, Lung, and Blood Institute.Vitamin B12-deficiency anemia.de Jager J, Kooy A, Lehert P, et al.Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: Randomised placebo controlled trial.BMJ. 2010;340:c2181. doi:10.1136/bmj.c2181Prescribers' Digital Reference.Metformin hydrochloride - drug summary.Dambha-Miller H, Day AJ, Strelitz J, Irving G, Griffin SJ.Behaviour change, weight loss and remission of type 2 diabetes: a community-based prospective cohort study.Diabet Med.2020;37(4):681-688. doi:10.1111/dme.14122American Diabetes Association.Eating well with diabetes.
MedlinePlus.Metformin.
DailyMed.Label: Metformin hydrochloride- metformin hydrochloride extended-release tablets tablet, film coated, extended release.
American Diabetes Association Professional Practice Committee.9. Pharmacologic approaches to glycemic treatment: Standards of medical care in diabetes—2022.Diabetes Care. 2022;45:S125-S143. doi:10.2337/dc22-S009
Rena G, Hardie DG, Pearson ER.The mechanisms of action of metformin.Diabetologia. 2017;60(9):1577-1585. doi:10.1007/s00125-017-4342-z
MedlinePlus.Type 2 diabetes.
Centers for Disease Control and Prevention.About insulin resistance and type 2 diabetes.
Centers for Disease Control and Prevention.About type 2 diabetes.
Food and Drug Administration.FDA drug safety communication: FDA revises warnings regarding use of the diabetes medicine metformin in certain patients with reduced kidney function.
MedlinePlus.Diabetes medicines.
American Diabetes Association.Diabetes and high blood pressure.
MedlinePlus.Blood glucose.
Adeva-Andany MM, Pérez-Felpete N, Fernández-Fernández C, Donapetry-García C, Pazos-García C.Liver glucose metabolism in humans.Bioscience Reports. 2016;36(6):e00416. doi:10.1042/BSR20160385
Holman RR, Paul SK, Bethel MA, Matthews DR, Neil HAW.10-year follow-up of intensive glucose control in type 2 diabetes.N Engl J Med. 2008;359:1577–1589. doi:10.1056/NEJMoa0806470
DailyMed. National Institutes of Health.Metformin hydrochloride tablet, film coated.
Derosa G, D’Angelo A, Romano D, Maffioli P.Effects of metformin extended release compared to immediate release formula on glycemic control and glycemic variability in patients with type 2 diabetes.Drug Des Devel Ther.2017;11:1481-1488. doi:10.2147%2FDDDT.S131670
National Heart, Lung, and Blood Institute.Vitamin B12-deficiency anemia.
de Jager J, Kooy A, Lehert P, et al.Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: Randomised placebo controlled trial.BMJ. 2010;340:c2181. doi:10.1136/bmj.c2181
Prescribers' Digital Reference.Metformin hydrochloride - drug summary.
Dambha-Miller H, Day AJ, Strelitz J, Irving G, Griffin SJ.Behaviour change, weight loss and remission of type 2 diabetes: a community-based prospective cohort study.Diabet Med.2020;37(4):681-688. doi:10.1111/dme.14122
American Diabetes Association.Eating well with diabetes.
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