Metformin is a generic drug that’s prescribed to treat high blood sugar levels caused by type 2 diabetes in adults and some children. Metformin comes as a tablet that’s typically taken one to three times per day.
Metformin belongs to a drug class called biguanides. Metformin is a generic medication.
This article describes the dosages of metformin, as well as its strengths and how to take it. To learn more about metformin, including its uses and side effects, see this metformin overview.
Note: This article describes typical dosages for metformin provided by the drug’s manufacturer. When taking metformin, always follow the dosage prescribed by your doctor.
The information below describes metformin’s typical dosages and other details about the drug.
Metformin form
Metformin comes in two oral forms: an extended-release (ER) tablet and an immediate-release (IR) tablet. “ER” means the drug is slowly released into your body over a long period of time. And “IR” means the drug is released into your body right away. IR is the standard tablet and is usually referred to simply as “oral tablet.”
Metformin strengths
The different forms of metformin come in the following strengths:
| Form | Strengths |
| oral tablet | • 500 milligrams (mg) • 850 mg • 1,000 mg |
| ER tablet | • 500 mg • 750 mg • 1,000 mg |
Typical dosages
Typically, your doctor will start by prescribing you a low dosage. Then they’ll adjust it over time to reach the amount that’s right for you. Your doctor will ultimately prescribe the smallest dosage that provides the desired effect.
The following information describes dosages that are commonly prescribed or recommended in adults. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs. In some cases, doctors may adjust your dosage from those shown below.
Dosage for type 2 diabetes
Doctors may prescribe metformin to manage blood sugar levels in adults with type 2 diabetes.
If your doctor prescribes metformin oral tablet, your starting dosage will likely be 500 mg twice per day or 850 mg once per day. Your doctor will likely increase your dosage in amounts of 500 mg every week or 850 mg every 2 weeks until your blood sugar levels are well managed. If your daily dose is greater than 2,000 mg, your doctor may prescribe the drug to be taken three times per day. The maximum dose per day is 2,550 mg.
If your doctor prescribes metformin ER tablet, the typical starting dosage is 500 mg once per day in the evening. Your doctor will increase the dosage in amounts of 500 mg per week until you reach your goal blood sugar levels. If your blood sugar levels aren’t well managed with once-daily dosing, your doctor may recommend you take the medication twice per day. The maximum dose per day is 2,000 mg.
For more information about your specific dosage, talk with your doctor.
Children’s dosage
Metformin oral tablet is approved to treat type 2 diabetes in children ages 10 years and older. Metformin ER tablet is not approved for use in children.
The recommended starting dosage of metformin for children is 500 mg twice per day. Your child’s doctor may increase your child’s dose in amounts of 500 mg per week until their blood sugar is well managed. The maximum dosage of metformin in children is 2,000 mg per day, which will likely be divided into 1,000 mg doses taken twice daily.
Talk with your child’s doctor if you have questions about their dosage.
How to take metformin
Metformin comes as an oral tablet that you swallow whole. Some metformin oral tablets are scored, which means they can be split in half along the score line (groove) if needed. However, metformin ER tablets should not be crushed, cut, or chewed. Be sure to take your dose with a meal or snack.
It may be helpful to take metformin around the same time of day. This helps maintain a steady level of the drug in your body so Metformin can work effectively.
If you have trouble swallowing tablets, see this article for tips on how to take this form of medication. You can also talk with your doctor or pharmacist.
Long-term treatment
Metformin is meant to be taken as a long-term treatment. If you and your doctor determine that metformin is safe and effective for you, you’ll likely take it long term.
Before you start taking metformin, your doctor will discuss your treatment plan with you.
ACCESSIBLE DRUG LABELS AND CONTAINERSSome pharmacies offer labels with large print, braille, or a code you scan with a smartphone to convert text to speech. If your local pharmacy doesn’t have these options, your doctor or pharmacist might be able to recommend a pharmacy that does.
If you’re having trouble opening medication bottles, ask your pharmacist about putting metformin in an easy-open container. They also may recommend tools that can make it easier to open bottles.
It’s important that you do not take more metformin than your doctor prescribes. For some medications, taking more than the recommended amount may lead to harmful effects or overdose.
Effects of an overdose
Overdose effects of metformin can include:
If you take more than the recommended amount of metformin
Call your doctor right away if you believe you’ve taken too much metformin. Another option is to call America’s Poison Centers at 800-222-1222 or use its online tool. If you have severe symptoms, immediately call 911 or your local emergency number, or go to the nearest emergency room.
Below are some frequently asked questions about metformin.
Is 500 mg considered a low dose of metformin?
Yes. The recommended starting dosage of metformin oral tablet is 500 milligrams (mg) twice per day. The typical starting dosage of metformin ER tablet is 500 mg once per day. So 500 mg is considered a low dose in most cases.
If you have concerns or questions about your dosage of metformin, talk with your doctor.
Can metformin be used for weight loss? If so, what’s the dosage?
Yes, metformin may be prescribed off-label for weight loss. With off-label use, doctors prescribe a drug for a purpose other than what the Food and Drug Administration (FDA) approved it for.
Because metformin isn’t approved for weight loss, the drug’s manufacturer doesn’t provide recommended dosages for this use. Your doctor will prescribe the dosage that’s right for you.
If you’d like to learn more about metformin for weight loss, talk with your doctor. You can also refer to this article for more information about metformin and weight loss.
When is the best time to take metformin?
The best time of day to take metformin depends on the form of the medication you’re prescribed. If you’re taking the oral tablet, the medication is typically taken twice per day with meals. If you’re taking the ER tablet, the medication is typically prescribed once per day with your evening meal.
If you have more questions about when to take metformin, talk with your doctor or pharmacist.
Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.