If you have type 2 diabetes, your doctor may recommend that you take metformin. It’s a prescription drug that can be used in adults and some children with this condition.
With type 2 diabetes, your body can’t regulate your blood sugar levels like usual.
You should use metformin together with a balanced, nutritious diet and exercise routine. This way, the drug will have a better effect on your blood sugar levels.
To learn more about type 2 diabetes and how metformin is used, see the “What is metformin used for?” section below.
Metformin oral tablet basics
Metformin is an active drug ingredient. It comes as an oral tablet that you’ll take by mouth. Metformin is classified as a biguanide.
Metformin is available as immediate-release tablets and extended-release tablets. Immediate-release tablets start working as soon as you take them. Extended-release tablets work over a certain period of time after you take them.
Read on to learn more about metformin’s side effects, how it’s taken, and more.
Note: Metformin also comes in an oral solution. But only the oral tablet form is described in this article. If you’d like to learn about metformin’s other forms, talk with your doctor or pharmacist.
Metformin oral tablet brand-name versions
Metformin immediate-release tablets are available as the brand-name drug Glucophage. And metformin extended-release tablets are available as the brand-name drugs Glumetza and Fortamet.
Note: The other forms of metformin are available as different brand-name drugs. To learn more about these versions, talk with your doctor or pharmacist.
Metformin oral tablet is a generic drug, which means it’s an exact copy of the active drug in a brand-name medication. The brand-name medication that it’s based on will depend on the form of metformin (immediate or extended release). It may be called Glumetza, Fortamet, or Glucophage.
Generic drugs are thought to be as safe and effective as the brand-name drug they’re based on. In general, generics usually cost less than brand-name drugs.
If you’d like to know more about using Glumetza, Fortamet, or Glucophage instead of metformin oral tablet, talk with your doctor. And see this Healthline article to learn more about the differences between generic and brand-name drugs.
Like most drugs, metformin oral tablets may cause mild or serious side effects. The lists below describe some of the more common side effects this drug may cause. These lists don’t include all possible side effects.
Keep in mind that side effects of a drug can depend on:
- your age
- other health conditions you have
- other medications you may be taking
Your doctor or pharmacist can tell you more about the potential side effects of metformin oral tablets. They can also suggest ways to help reduce side effects.
Mild side effects
Here are some of the mild side effects metformin oral tablets can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read metformin oral tablet’s prescribing information.
Mild side effects of metformin oral tablets that have been reported include:
- diarrhea*
- nausea or vomiting
- gas
- indigestion
- belly discomfort
- headache
- weight loss (to learn more about this, see the “Metformin and weight loss” section below)
Mild side effects of many drugs may go away within a few days or a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.
* For more information on this side effect, see the “Side effect focus” section below.
Serious side effects
Serious side effects from metformin oral tablets can occur, but they aren’t common. If you have serious side effects from metformin oral tablets, call your doctor right away. However, if you think you’re having a medical emergency, you should call 911 or your local emergency number.
Serious side effects of metformin oral tablets that have been reported include:
- low vitamin B12 level
- hypoglycemia (low blood sugar level)*
- boxed warning: lactic acidosis*
- allergic reaction*
* For more information on this side effect, see the “Side effect focus” section below.
How long side effects last
The length of time that your side effects from metformin will last depends on which side effects you’re having. For example, diarrhea may occur when you first start taking this drug. But over time, this side effect may go away.
Other side effects, such as a low vitamin B12 level, may remain for however long you’re taking metformin.
If you’re having side effects from metformin oral tablets, tell your doctor. They’ll be able to help you determine how long the side effects may last. They may also be able to suggest ways to decrease your side effects.
Side effect focus
Learn more about some of the side effects metformin oral tablets may cause.
Boxed warning
Metformin oral tablets have a
Lactic acidosis. Some people taking metformin have had lactic acidosis. Lactic acidosis can occur if your body can’t get rid of lactic acid quickly enough. With this condition, there’s a buildup of lactic acid in your blood.
Although rare, this side effect is possible with metformin oral tablets. And it can be serious or even life threatening.
You should be aware of the symptoms of lactic acidosis. This way, you can get treatment right away if you develop symptoms of the condition. Symptoms to watch out for include:
- muscle pain
- trouble breathing
- sleepiness
- belly pain
What might help
If you develop any symptoms of lactic acidosis, tell your doctor right away. You’ll likely need to go to the hospital for treatment for lactic acidosis.
Also, be sure to talk with your doctor about your risk for having lactic acidosis before starting metformin. Sometimes, other medical conditions or medications can increase your risk of developing lactic acidosis.
For example, you may have an increased risk for lactic acidosis if you:
- have kidney or liver problems
- are ages 65 years or older
- are receiving contrast dye for CT scans or X-rays
- are having surgery
- have congestive heart failure
- drink large amounts of alcohol
- take certain medications, such as topiramate (Topamax)
Talk with your doctor about your risk for lactic acidosis. They’ll likely recommend that you monitor for symptoms and get medical help right away if symptoms develop. If you have certain conditions that may increase your risk for lactic acidosis, your doctor may recommend a medication other than metformin for you.
If you have more questions about metformin and lactic acidosis, talk with your doctor or pharmacist.
Diarrhea
You may have diarrhea while you’re taking metformin oral tablets. Diarrhea is one of the most common side effects of this medication.
It’s possible to have diarrhea when you first start taking metformin or when your doctor increases your dosage of the drug. But usually, diarrhea goes away over time and you won’t have it after taking the drug for a while.
What might help
If you get diarrhea while you’re taking metformin, be sure to stay hydrated. Diarrhea can cause dehydration (low fluid level in your body). And this can increase your risk for other side effects of metformin even more.
Talk with your doctor about this possible side effect of metformin. Your doctor may recommend that you take another medication to decrease diarrhea with this drug.
In most cases, diarrhea is a temporary side effect of metformin. And after you’ve been taking the drug for a while, diarrhea will usually go away.
If you have more questions about metformin and diarrhea, talk with your doctor or pharmacist.
Hypoglycemia
Hypoglycemia is a possible side effect of metformin, when it’s used together with other drugs to treat type 2 diabetes. These other drugs include glipizide (Glucotrol), glyburide (DiaBeta), or insulin drugs.
With hypoglycemia, your blood sugar level gets too low, which can be very serious or even life threatening.
This side effect is serious, and it’s a common side effect of metformin.
You should be aware of symptoms of hypoglycemia. This way, you can treat the condition right away if you develop symptoms. Symptoms of hypoglycemia may include:
- dizziness
- sweating
- increased heart rate
- confusion
- blurry vision
- headache
- hunger
- feeling jittery
What might help
Your doctor will likely recommend that you check your blood sugar level during diabetes treatment. This is important so that you can recognize when your blood sugar becomes too low or too high.
If you have symptoms of hypoglycemia, you should treat the condition right away. The American Diabetes Association recommends that you:
- Eat 15 grams (g) of carbohydrates, and then wait 15 minutes and check your blood sugar level.
- If your blood sugar level is still less than 70 milligrams per deciliter (mg/dL), you should eat another 15 g of carbohydrates.
- Then, wait another 15 minutes and check your blood sugar level again.
- You may have to repeat these steps until your blood sugar level is above 70 mg/dL.
Examples of foods that contain about 15 g of carbohydrates include:
- three or four 4-gram glucose tablets
- a container of glucose gel that holds 15 g of carbohydrates
- candies such as jellybeans and gum drops
- 4 ounces of juice or soda, but not diet soda
- 1 tablespoon of honey or sugar
Be sure to treat low blood sugar level right away. Not treating it can cause you to faint or even have a seizure. If you have low blood sugar and can’t eat or swallow, you’ll likely need an injection of glucagon (Gvoke, Baqsimi). And you may need to have someone take you to the hospital or call 911 or a local emergency number for help.
If you do have hypoglycemia with metformin, be sure to tell your doctor about it. In some cases, they may recommend a lower dose of your diabetes medications. This may help reduce your risk for low blood sugar levels.
Allergic reactionSome people may have an allergic reaction to metformin oral tablets.
Symptoms of a mild allergic reaction can include:
- skin rash
- itchiness
- flushing (temporary warmth, redness, or deepening of skin color)
A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include swelling under your skin, typically in your eyelids, lips, hands, or feet. They can also include swelling of your tongue, mouth, or throat, which can cause trouble breathing.
Call your doctor right away if you have an allergic reaction to metformin oral tablets. But if you think you’re having a medical emergency, call 911 or your local emergency number.
At this time, metformin is not approved to be used for weight loss. But even though it’s not approved for weight loss, metformin may help some people to lose weight. In fact, weight loss is a possible side effect of this drug.
It’s not known exactly how metformin use may lead to weight loss. But metformin shouldn’t cause weight gain.
There’s no recommended dosage of metformin for weight loss because the drug is not approved for this use.
If you have any questions about metformin and weight loss, talk with your doctor.
If you have type 2 diabetes, your doctor may recommend that you take metformin. It’s a prescription drug that can be used in adults and some children with this condition.
With type 2 diabetes, your body can’t regulate your blood sugar levels like usual.
Normally, your body regulates your blood sugar level by releasing insulin. Insulin is a hormone that helps your body use sugar as energy. But people with type 2 diabetes may not make enough insulin, or they may have insulin resistance. (With insulin resistance, your body doesn’t respond as well as usual to insulin.) So the hormone doesn’t work like it should, resulting in increased blood sugar levels.
Metformin works to treat type 2 diabetes by helping to lower your blood sugar levels. For more details about how it works, see the “What are some frequently asked questions about metformin?” section above.
You should use metformin together with a balanced, nutritious diet and exercise routine. This way, the drug will have a better effect on your blood sugar levels.
Metformin oral tablets come in an immediate-release form and an extended-release form. To learn more about these forms, see the “How is metformin taken?” section above. Immediate-release metformin tablets can be used in adults and children ages 10 years and older. Extended-release metformin tablets can be used in adults, but not in children.
In some cases, metformin may be used to treat prediabetes. With prediabetes, your blood sugar level is higher than normal, but it’s not high enough to be considered diabetes. Prediabetes can be a sign that you’re going to develop diabetes. Managing prediabetes is an off-label use of metformin oral tablets. (With off-label use, a drug is given for a condition other than what it’s approved to treat.)
If you have questions about how metformin is used, talk with your doctor or pharmacist.
Your doctor will recommend the dosage of metformin oral tablet that’s right for you. Below are commonly used dosages, but always take the dosage your doctor prescribes.
Forms and strengths
Metformin oral tablets are taken by mouth. They’re available as immediate-release tablets and extended-release tablets.
Immediate-release tablets start working as soon as you take them. Extended-release tablets work over a certain period of time after you take them.
Because metformin is available in both an immediate-release form and an extended-release form, it comes in several strengths. For instance:
- immediate-release metformin oral tablets are available as:
- 500 milligram (mg)
- 850 mg
- 1,000 mg
- extended-release metformin oral tablets are available as:
- 500 mg
- 750 mg
- 1,000 mg
Recommended dosage
The dosage of metformin oral tablets your doctor prescribes for you will depend on the type of tablets you’re taking. Below, we describe typical dosages for immediate-release tablets and extended-release tablets.
Dosage of immediate-release metformin oral tablets
The lowest recommended dosage of immediate-release metformin oral tablets is a starting dosage of 500 mg taken twice daily with a meal. In some cases, your doctor may recommend a starting dosage of 850 mg taken once daily with a meal.
Your doctor may recommend increasing your dosage every week. If you’re taking more than 2,000 mg of metformin each day, your doctor may recommend that you take the medication three times each day.
The maximum recommended dose of immediate-release metformin oral tablets is 2,550 mg daily.
Below is a sample dosage chart for immediate-release metformin oral tablet. But your dosage may depend on how well your blood sugar level is managed with this drug. Always follow the dosage that your doctor prescribes for you.
| Week of treatment | Morning dose | Evening dose |
| week 1 | 500 mg | 500 mg |
| week 2 | 1,000 mg | 500 mg |
| week 3 | 1,000 mg | 1,000 mg |
| week 4 | 1,500 mg | 1,000 mg |
Dosage of extended-release metformin oral tablets
The recommended starting dosage of extended-release metformin oral tablets is 500 mg taken once daily, with your evening meal. Your doctor may increase your dosage by 500 mg every week or 2 weeks.
The maximum recommended dose of extended-release metformin oral tablets is 2,000 mg once daily.
Below is a sample dosage chart for extended-release metformin oral tablet. But your dosage may depend on how well your blood sugar level is managed. Always follow the dosage that your doctor prescribes for you.
| Week of treatment | Evening dose |
| week 1 | 500 mg |
| week 2 | 1,000 mg |
| week 3 | 1,500 mg |
| week 4 | 2,000 mg |
When to take metformin oral tablet
When you’ll take metformin oral tablets depends on which form of the medication you’re taking. For instance, if you’re taking:
- immediate-release metformin tablets, you should take them twice daily with meals. Some people prefer to take their dose with breakfast and dinner.
- extended-release metformin tablets, you only need to take them once each day. And you should take your dose with your evening meal.
Taking metformin at night
If you’re taking extended-release metformin, you should take your dose once daily at night, with your last meal of the day. Doing so allows the drug to work properly in reducing your blood sugar level.
If you have any questions about the best time of day to take metformin, talk with your doctor or pharmacist.
Questions about metformin oral tablet’s dosage
Below are some common questions about metformin oral tablet’s dosage.
- What if I miss a dose of metformin oral tablets? If you miss a dose of metformin oral tablets, skip the missed dose. Then, take your next dose on your usual schedule. Never take two doses at once to make up for a missed dose.
- Will I need to use metformin oral tablets long term? If metformin oral tablets work for you, you’ll likely take them long term.
- How long do metformin oral tablets take to work? Metformin oral tablets begin working as soon as you take them. It takes longer to begin working than injectable drugs because it’s taken by mouth. So if you need to lower your blood sugar level quickly, your doctor may recommend that you use a fast-acting insulin drug. For more information about this, talk with your doctor.
Your doctor will explain how you should take metformin oral tablets. They’ll also explain how much to take and how often. Be sure to follow your doctor’s instructions.
Taking metformin oral tablet
Metformin oral tablets are taken by mouth. They’re available as immediate-release tablets and extended-release tablets.
Immediate-release tablets start working as soon as you take them. Extended-release tablets work over a certain period of time after you take them.
When to take metformin oral tablet
When you’ll take metformin oral tablets depends on which form of the medication you’re taking. For instance, if you’re taking:
- immediate-release metformin tablets, you should take them twice daily with meals. Some people prefer to take their dose with breakfast and dinner.
- extended-release metformin tablets, you only need to take them once each day. And you should take your dose with your evening meal.
Taking metformin oral tablet with other drugs
Sometimes, taking just one medication isn’t enough to treat type 2 diabetes.
Your doctor may start you out with metformin. But if it’s not managing your blood sugar levels well enough, your doctor may recommend that you take other diabetes medications together with metformin.
Examples of other medications your doctor may recommend that you take with metformin include:
- empagliflozin (Jardiance)
- dulaglutide (Trulicity)
- dapagliflozin (Farxiga)
- sitagliptin (Januvia)
- glipizide (Glucotrol)
- glyburide (DiaBeta)
- glimepiride (Amaryl)
- insulin, such as insulin glargine (Lantus) or insulin lispro (Humalog)
If you have questions about taking other medications along with metformin, talk with your doctor or pharmacist.
Questions about taking metformin oral tablet
Here’s a list of common questions related to taking metformin oral tablets.
- Can metformin oral tablets be chewed, crushed, or split? You may crush or split immediate-release metformin tablets. But you should never break, crush, or chew extended-release metformin tablets. This is because breaking, crushing, or chewing the tablets changes the way they work in your body. If you’re having trouble swallowing the tablets, talk with your doctor. They may recommend taking a different medication or using the liquid form of metformin that’s taken by mouth.
- Should I take metformin oral tablets with food? Yes, you should take your doses of metformin oral tablets with food. The immediate-release form is taken twice daily with meals, and the extended-release form is taken once daily with your evening meal.
Questions for your doctorYou may have questions about metformin oral tablets and your treatment plan. It’s important to discuss all your concerns with your doctor.
Here are a few tips that might help guide your discussion:
- Before your appointment, write down questions like:
- How will metformin oral tablets affect my body, mood, or lifestyle?
- Bring someone with you to your appointment if doing so will help you feel more comfortable.
- If you don’t understand something related to your condition or treatment, ask your doctor to explain it to you.
Remember, your doctor and other healthcare professionals are available to help you. And they want you to get the best care possible. So don’t be afraid to ask questions or offer feedback on your treatment.
Find answers to some commonly asked questions about metformin oral tablet.
Is metformin used for PCOS or fertility problems? If so, what’s the dosage?
Metformin is not approved to treat polycystic ovary syndrome (PCOS) or fertility problems.
PCOS is a hormone condition that can occur in females.* It may cause irregular periods and also lead to fertility problems. Additionally, with PCOS, you can have insulin resistance (a condition in which your body doesn’t respond to insulin like usual). Insulin resistance can contribute to certain symptoms of PCOS, such as weight gain.
In some cases, metformin is used off-label to treat PCOS or help with fertility problems. (With off-label use, a drug is used for a condition other than what it’s approved to treat.)
The drug can reduce insulin resistance so that your body can use insulin properly. This can lower your blood sugar level. And in people with PCOS, normal menstrual cycles may occur, decreasing fertility issues.
Because metformin is not approved to treat PCOS or fertility problems, there’s no approved dosage of the drug for these purposes.
If you’re interested in taking metformin to treat PCOS or fertility problems, talk with your doctor. They may discuss this treatment option with you and recommend a proper dose.
* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.
How does metformin work? And how long does it stay in your system?
Metformin works to treat type 2 diabetes in certain people. With type 2 diabetes, your body can’t regulate your blood sugar level like usual.
Normally, your body regulates your blood sugar level by releasing insulin. Insulin is a hormone that helps your body use sugar as energy. But people with type 2 diabetes may not make enough insulin, or they may have insulin resistance. (With insulin resistance, your body doesn’t respond as well as usual to insulin.) So the hormone doesn’t work like it should, resulting in increased blood sugar levels.
Metformin works in these ways to treat type 2 diabetes:
- decreases blood sugar that’s made by your liver
- decreases your body’s absorption of sugar from your food
- makes your body more sensitive to insulin, so that the hormone works better to decrease your blood sugar level
How long a drug stays in your system is related to the drug’s half-life. The half-life of a drug tells how long it takes for your body to get rid of half of a dose of the drug.
The half-life of metformin is about 6 hours and 12 minutes. So after this length of time, your body has cleared half of a dose of the drug. In general, it takes about four to five half-lives for your body to clear an entire dose of a drug.
Studies show that your body gets rid of about 90% of a dose of metformin through your kidneys within 24 hours of taking it. This is why it is important to take metformin doses every day.
Are there alternatives to metformin? What about natural alternatives such as berberine?
Yes, there are other treatment options besides metformin for type 2 diabetes. But metformin is recommended in the American Diabetes Association’s guidelines as the preferred first treatment option for people with type 2 diabetes. In some cases, though, people may be allergic to metformin. Or they may have side effects from the medication.
Many other options for diabetes treatment are available in addition to metformin. This includes other drugs taken by mouth, drugs given by injection, and even certain natural supplements.
Examples of other drugs taken by mouth that can be used for type 2 diabetes include:
- sitagliptin (Januvia)
- linagliptin (Tradjenta)
- canagliflozin (Invokana)
- dapagliflozin (Farxiga)
- pioglitazone (Actos)
- glimepiride (Amaryl)
- glipizide (Glucotrol)
Examples of drugs given by injection that can be used for type 2 diabetes include:
- dulaglutide (Trulicity)
- semaglutide (Ozempic)
- insulin lispro (Humalog)
- insulin aspart (Novolog)
- insulin glargine (Lantus)
Additionally, some natural supplements may be beneficial in decreasing blood sugar levels. But keep in mind that supplements do not go through the same studies as prescription drugs. And they’re not approved for use by the Food and Drug Administration (FDA).
It’s not known how well supplements may work to treat diabetes, if at all. Examples of some supplements that may be used for diabetes include:
- berberine
- cinnamon
- coenzyme Q10
- turmeric
- vinegar
Before starting any supplements, be sure to talk with your doctor or pharmacist. Although supplements are available over the counter, they may interact with your prescription medications. So always check with your doctor before taking one.
If you’re interested in using a treatment for type 2 diabetes other than metformin, talk with your doctor.
Does metformin increase the risk of cancer?
No, metformin isn’t known to increase your risk for developing cancer.
But recently, the FDA recalled some metformin tablets because the tablets contained unsafe levels of a chemical called N-nitrosodimethylamine (NDMA). This chemical is a carcinogen, which means it can increase the risk of cancer.
The most updated list of recalled metformin products is available through the
Taking metformin tablets that contain levels of NDMA that are over the safe limit may increase the risk of cancer. But taking FDA-approved metformin tablets that were not part of the recall does not increase your risk for cancer.
In fact, metformin is currently being tested as part of a treatment regimen for breast cancer and prostate cancer. But at this time, it’s not known if metformin may have a role in cancer treatment.
Are metformin’s side effects in males different than its side effects in females?
In most cases, side effects are similar in both females and males taking metformin.*
A study was done to compare the side effects of metformin reported by females with those reported by males. The study showed that females had side effects more often than males. But both groups reported the same most common side effects.
In this study, the most common side effects reported by both males and females were:
- diarrhea
- nausea
- belly pain
- gas
- headache
- fatigue (lack of energy)
If you have questions about side effects you’re having with metformin, talk with your doctor or pharmacist.
* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.
Is metformin used in antiaging therapy?
No, at this time, metformin is not approved for antiaging therapy. It’s possible that the drug may help manage diseases related to aging. But it’s not known how well, if at all, the drug may work for antiaging.
Metformin is being
If you’d like to know more about antiaging treatments, talk with your doctor.
Taking medications, vaccines, foods, and other things with a certain drug can affect how the drug works. These effects are called interactions.
Before taking metformin oral tablet, be sure to tell your doctor about all medications you take, including prescription and over-the-counter types. Also describe any vitamins, herbs, or supplements you use. Your doctor or pharmacist can tell you about any interactions these items may cause with metformin oral tablets.
Interactions with drugs or supplements
Metformin oral tablets can interact with several types of drugs. These drugs include:
- other diabetes medications that lower your blood sugar level, such as insulin
- the cholesterol supplement nicotinic acid
- certain seizure drugs, including topiramate or phenytoin
- the heartburn drug cimetidine
- certain antipsychotic drugs, such as chlorpromazine
- some hormone medications, including birth control pills
- certain blood pressure medications, such as hydrochlorothiazide
- steroid medications, such as prednisone
- thyroid medications, including levothyroxine
- the tuberculosis medication isoniazid
- the HIV medication dolutegravir
This list does not contain all types of drugs that may interact with metformin oral tablets. Your doctor or pharmacist can tell you more about these interactions and any others that may occur with use of metformin oral tablets.
Other interactions
You don’t need to avoid any foods while you’re taking metformin oral tablets. This includes grapefruit, which should be avoided when you’re taking certain other drugs.
It’s important to discuss with your doctor all of your medical conditions before starting treatment with metformin. Some health considerations are described in more detail below.
Boxed warning
Metformin oral tablet has a
Lactic acidosis can occur if your body can’t get rid of lactic acid quickly enough. With this condition, there’s a buildup of lactic acid in your blood.
Although rare, this side effect is possible with metformin oral tablets. And it can be serious or even life threatening.
For more information, see the “What are metformin’s side effects?” section above.
Other warnings
Metformin oral tablet may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take metformin oral tablet. Factors to consider include those in the list below.
- Kidney problems. If you have kidney problems, your doctor may recommend a medication other than metformin oral tablets for you. Taking metformin when you have kidney problems can increase your risk of lactic acidosis. (See the “Boxed warning” section just above for information about lactic acidosis.) Metformin has a contraindication against its use in people with severe kidney problems. This means that the drug should never be used by this group of people. If you have kidney problems, talk with your doctor before taking metformin.
- Allergic reaction. If you’ve had an allergic reaction to metformin oral tablets or any of their ingredients, you should not take the drug. Ask your doctor what other medications are better options for you.
- Liver problems. If you have liver problems, your doctor may prescribe a medication other than metformin oral tablets for you. This is because liver problems can increase your risk for lactic acidosis. If you have liver problems, talk with your doctor about treatment options that are safe for you.
- Heart problems. If you have certain heart problems, such as congestive heart failure, tell your doctor before starting metformin oral tablets. These conditions may increase your risk for lactic acidosis. If you have any problems with your heart, talk with your doctor before starting metformin.
- Diabetic ketoacidosis. You should not use metformin if you have a complication of diabetes called diabetic ketoacidosis (DKA). In fact, metformin has a contraindication against its use in people with DKA. This means that the drug should never be used in people with DKA or other forms of acidosis.
- Upcoming surgery or certain imaging tests. If you have an upcoming surgery or a certain imaging test that uses contrast dye, tell your doctor if you’re taking metformin oral tablets. They may recommend that you stop taking metformin for a few days prior to your surgery or procedure.
- Type 1 diabetes. Metformin should not be used to treat type 1 diabetes. Instead, it’s used to treat type 2 diabetes. If you have type 1 diabetes, talk with your doctor about treatment options that are right for your condition.
Use with alcohol
You should not drink alcohol if you’re taking metformin. Alcohol increases your risk for developing lactic acidosis with metformin. In fact, metformin oral tablets have a
Lactic acidosis can occur if your body can’t get rid of lactic acid quickly enough. With this condition, there’s a buildup of lactic acid in your blood. Lactic acidosis can be serious or even life threatening.
Also, if you drink sugary alcoholic drinks, your blood sugar level may increase. And keep in mind that metformin is used to help lower your blood sugar level.
Pregnancy and breastfeeding
It’s not known if metformin is safe to take during pregnancy. At this time, there aren’t enough studies available to know if the drug is a safe treatment option.
Studies have shown that metformin passes into breast milk. But it’s not known what effects metformin may have on a child who’s breastfed.
If you’re pregnant, breastfeeding, or planning either, talk with your doctor before starting metformin. They may recommend a different medication for you.
Do not take more metformin oral tablets than your doctor prescribes. Using more than this can lead to serious side effects.
Symptoms of overdose
Symptoms caused by an overdose can include:
- hypoglycemia (low blood sugar level)
- lactic acidosis (buildup of lactic acid in your blood), which may cause:
- muscle pain
- trouble breathing
- sleepiness
What to do in case you take too much metformin oral tablet
Call your doctor if you think you’ve taken too much metformin. You can also call 800-222-1222 to reach the American Association of Poison Control Centers or use their online resource. However, if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.
Costs of prescription drugs can vary depending on many factors. These factors include what your insurance plan covers and which pharmacy you use.
Financial assistance to help you pay for metformin oral tablet may be available. Medicine Assistance Tool and NeedyMeds are two websites that provide resources to help reduce the cost of metformin oral tablets.
These websites also offer tools to help you find low-cost healthcare and certain educational resources. To learn more, visit their websites.
If you have type 2 diabetes, your doctor may recommend that you take metformin. It’s a prescription drug that can be used in adults and some children with this condition.
Metformin oral tablets may cause certain side effects, some of which can be serious. In most cases, though, metformin side effects are mild. If you have specific questions about side effects of this drug, discuss them with your doctor or pharmacist.
Here are some possible questions you may wish to ask your doctor before starting metformin:
- Does metformin use lead to dementia?
- Is there an increased risk of side effects if I’m taking multiple medications for diabetes?
- If I become pregnant while I’m taking metformin, should I stop the medication?
- How much should I expect metformin to lower my blood sugar level?
- Can I switch between immediate-release and extended-release metformin oral tablets?
If you have more questions about metformin, see this article, which describes common treatments for diabetes. You may also wish to read this article, which presents alternative treatments for diabetes.
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Q:
If my blood sugar level is too high, can I treat it by taking an extra metformin tablet?
Anonymous
A:
It’s important to talk with your doctor before taking more metformin oral tablets than prescribed.
Taking too much metformin may cause hypoglycemia (low blood sugar level). This is especially the case if you’re taking other medications with metformin to manage diabetes.
When you first start taking metformin, your doctor may increase your dosage once every 1 or 2 weeks depending on:
- the form of metformin tablets you’re prescribed
- your blood sugar levels
If you have symptoms of hyperglycemia (high blood sugar level), call your doctor right away. This could be a rare complication of type 2 diabetes known as diabetic ketoacidosis (DKA). And DKA is considered a medical emergency.
Possible symptoms of hyperglycemia to watch for include:
- breath that smells fruity
- weakness
- shortness of breath
The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
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