COMMON BRANDS: Glucophage, Glumetza, Glucophage XR, Fortamet, Glyciphage

Metformin is a prescription medicine relates to a class of drugs called biguanides. It is commonly used for type 2 diabetic patients. The drug is available either as an oral tablet and an oral solution.

Metformin tablets are available in two forms immediate-release and extended-release. The immediate-release tablet comes with the brand name Glucophage. The extended-release tablet is available with brand name Glucophage XR, Fortamet, and Glumetza.

What is Metformin used for?

Metformin along with an appropriate diet and exercise and likely with other drugs helps to control blood sugar level. This drug is commonly prescribed for type 2 diabetic patients. Maintaining high blood sugar level helps to prevent kidney damage, blindness, nerve problems, loss of limbs, and sexual function problems. Maintained sugar level avoid the risk of a heart attack or stroke.

Metformin helps to restore your body’s proper response to the insulin you naturally produce by the pancreas. It further reduces the quantity of sugar that your liver produces and that your stomach or intestines consume.

Metformin helps to maintain regular menstrual cycle and lowers body mass index (BMI), luteinizing hormone (LH) and testosterone within six months of treatment in women with polycystic ovary syndrome (PCOS).

How to use Metformin?

Read the Information Leaflet if available from your pharmacist before you begin using metformin and every time you get a refill. Any questions regarding this medication, ask your physician or pharmacist.

Take this medication orally as advised by your doctor, usually 1-3 times a day with meals. Drink plenty of liquid while taking this medicine unless otherwise directed by your physician.

The dosage is based on your diagnosis, response to treatment, and different medications you may be using. Make sure to tell your physician and pharmacist about all the products you use (including prescription medications, nonprescription medications, and herbal products). To reduce your chance of side effects (such as stomach upset), your physician may direct you to begin this medication at a low dosage and gradually increase your dosage. Obey your doctor’s guidance attentively.

Take this drug regularly benefit the most out of it. Do not forget to use this medication at the same times every day.

If you are already using another diabetic drug (For example chlorpropamide), follow your doctor’s directions correctly for ending/continuing the old drug and starting metformin.

Monitor your blood glucose levels regularly as directed by your physician. Keep track of the results, and inform them to your doctor. Tell your doctor if your blood glucose level ranges are too high or too low. Your dosage/treatment may need to be replaced.

What are the side effects of Metformin?

This drug may cause nausea, vomiting, diarrhea, stomach upset, weakness, or a metallic taste of mouth. If any of these effects prolong or worsen, inform your doctor or pharmacist as soon as possible. If stomach problems return later (after taking the same dose for several days or weeks), tell your doctor immediately. Stomach problems that may occur after the first few days of your treatment may be a sign of lactic acidosis.

Remember that your doctor has recommended this medication because your doctor has found that the benefits to you are higher than the risk of side effects. Many people using this medication do not experience any severe side effects.

Metformin normally does not cause low blood sugar level (hypoglycemia). Low blood sugar may be the result of using other diabetes drugs in combination with this drug. Inform your doctor or pharmacist about whether the dose of your other diabetes medication needs to be reduced.

Symptoms of low blood sugar include sudden shivering, sweating, shaking, fast heartbeat, blurred vision, hunger, dizziness, or tingling hands or feet. It is a good practice to carry glucose tablets or gel to treat a sudden low blood sugar level. If you don’t have these forms of glucose, a quick source of sugar such as sugar table, honey, sugar candy, or drink juice or a non-diet soda. Low blood sugar may occur if you drink a large quantity of alcohol, doing an unusually heavy workout, or not consuming enough calories from food. To prevent drop blood sugar level, eat meals on a regular schedule, and do not miss meals.

Symptoms of hyperglycemia (high blood sugar levels) may include thirst, flushing, rapid breathing, increased urination, confusion, drowsiness, and fruity breath odour. If you observe any of these symptoms, inform your doctor as soon as possible. Your doctor may adjust your diabetes medication if needed.

Stop taking this medication and inform your doctor immediately if this severe side effect occurs like lactic acidosis.

A severe allergic reaction to this drug is very uncommon. However, get medical assistance immediately if you notice any of the following symptoms like allergic reaction: rash, severe dizziness, trouble breathing itching/swelling (especially of the face/tongue/throat).

This does not include the list of all possible side effects. If you observe other side effects not listed above, please contact your doctor or pharmacist for further information.

What are the precautions while using Metformin?

Before starting this medication, tell your physician or pharmacist if you have any allergy to metformin or if you have some different allergies. Some brands may include inactive ingredients, which may cause allergic reactions or various problems. Speak to your doctor or pharmacist for further information.

Before starting this medication, tell your physician or pharmacist about your medical history, especially if you have severe breathing problems (For example obstructive lung disease, severe asthma), blood problems (For example anaemia, vitamin B12 deficiency), liver disease, kidney issues.

Before having surgery or any scanning/X-ray procedure using iodinated contrast, tell your physician about all the products you are using (also herbal products and prescription medications/ nonprescription medications). You may need to hold the use of this medication for a short period for the surgery. Seek your doctor or dentist advise before your procedure/surgery.

You may also experience blurred vision, drowsiness or dizziness, due to extremely high or low blood sugar level. Don’t drive or operate any machinery, or perform any activity that needs a clear vision or alertness unless you are sure you can make such tasks carefully.

Limit consumption of alcohol while taking this medication because it can trigger your chances of having low blood sugar and developing lactic acidosis.

High fever, diuretics such as hydrochlorothiazide, high sweating, diarrhoea, or vomiting may cause dehydration (loss of body water) and higher your risk for lactic acidosis. Stop using this medication and tell your physician immediately if you have continued diarrhoea or vomiting. Make sure to take lots of fluids to limit dehydration unless your physician tells you.

It may be difficult to control your blood sugar level when your body is under stress (such as due to fever, injury, infection, or surgery). Consult your physician because increased stress may require a different treatment plan, medications, or blood glucose test.

Older adult individuals may be at higher risk for side effects such as lactic acidosis or low blood sugar.

During pregnancy, this medication should be taken only when needed. Discuss the benefits and risks with your physician. Your physician may advise you to use insulin instead of this medication during your pregnancy. Follow your doctor’s advice carefully.

Metformin can cause alterations in the menstrual cycle (promote ovulation) and increase the chances of pregnancy. Ask your physician or pharmacist about the use of proper birth control while using this medication.

Metformin can pass into breast milk in small quantities. Consult your doctor before breastfeeding.

What are the drug interactions of Metformin?

Metformin can interact with other medicines, vitamins, or herbs you may be using. A drug interaction occurs when a substance alters the way a medication works. It may be harmful or restrict the drug from proper working.

To prevent drug interactions, your physician should manage all of your medicines carefully. Make sure to inform your prescriber about all drugs, vitamins, or herbs you are using. To obtain information regarding how metformin might interact with something else you are taking, talk to your doctor or pharmacist.

Examples of drugs which can cause interactions with metformin are listed below.

Diabetes drugs:

Taking other diabetes drugs with metformin can lower your blood sugar level. If you start using metformin, your physician may decrease the dosage of your other diabetes medications. For example Insulin medicines that release insulin such as glyburide.

Blood pressure drugs:

Beta-blocker drugs such as metoprolol, propranolol, glaucoma eye drops such as timolol may hinder the fast or pounding heartbeat you would generally feel when your blood sugar level falls too low (hypoglycemia). Another symptoms of low blood glucose, such as dizziness, hunger, or sweating, are not affected by these drugs.

Cholesterol drug:

Taking metformin along with nicotinic acid may decrease the effectiveness of metformin in lowering blood sugar level.


Using metformin with phenytoin, decrease the effectiveness of metformin in lowering blood sugar.

GIT drugs:

Using metformin with cimetidine (H2 blockers) may raise the risk of lactic acidosis.


Using metformin with phenothiazines (antipsychotic medications) may reduce metformin effect in lowering blood sugar. For example chlorpromazine, fluphenazine and prochlorperazine.

Hormonal drugs:

Corticosteroids such as budesonide, fluticasone, prednisone, and betamethasone. Were as estrogens such as hormonal birth control, including birth control pills or patches and conjugated estrogens estradiol, may decrease the effect of metformin in maintaining blood sugar level.


Prolong use of metformin in high concentrations can sometimes build up in the body and can cause lactic acidosis, which can be serious and in some cases fatal. Lactic acidosis is more likely to happen in older adults if you have a kidney or liver disease, dehydration, heavy alcohol use, if you have to undergo surgery, heart failure, if you have scanning or X-ray procedures that use iodinated contrast, or if you are using other drugs. For some conditions, your doctor may advise you to stop taking metformin for a short time. Ask your doctor/pharmacist for further details.

Stop taking this medication and get medical advice as soon as possible if you have any of these symptoms of lactic acidosis, like unusual tiredness, dizziness, severe drowsiness, chills, stomach pain with nausea/vomiting/ diarrhoea, blue/cold skin, muscle pain, fast/difficult breathing, or slow/irregular heartbeat.

What are the forms and strengths of Metformin?

Generic name: Metformin.
Form: Immediate release oral tablet.
Strengths: 500mg, 850mg, 1000mg.
Form: Extended-release oral tablet.
Strengths: 500mg, 750mg, 1000mg.

Brand name: Glucophage.
Form: Immediate release oral tablet.
Strengths: 500mg, 850mg, 1000mg.

Brand name: Glucophage XR.
Form: Extended-release oral tablet.
Strengths: 500mg, 750mg.

Brand name: Fortamet.
Form: Extended-release oral tablet.
Strengths: 500mg, 1000mg.

Brand name: Glumetza.
Form: Extended-release oral tablet.
Strengths: 500mg, 1000mg.

What is the dosage of Metformin?

For Type 2 Diabetes:

Adults (18–79 years):

Starting dosage (Immediate release tablets):

500mg twice a day, or 850mg once a day. Take your doses along with meals.


Children (10–17 years):

Starting dosage (Immediate release tablets):

500mg twice a day.

Children (0–9 years):

This drug is not studied in children under 10 years of age and shouldn’t be given.


Older adults (80 years and above):

People aged 80 years and above shouldn’t start taking metformin unless they have no kidney related problems. People at these ages have a higher risk of lactic acidosis. If your age is 80 years or older maximum dose of metformin should be avoided.

Most common questions asked about Metformin / Q&A’s:

What does Metformin do to your body?

Metformin is classified as a biguanide drug. These drugs work by lowering the sugar level in the blood of people with diabetes. This happens by reducing the amount of sugar produced by the liver and also by increasing the sensitivity of muscle cells to insulin.

Can Metformin be used for weight loss in non-diabetics?

Metformin is used off-label in PCOS to prevent diabetes and increase ovulation through weight loss and hormonal control. Some studies have shown that metformin can be used in overweight and obese euglycemic patients.

Why does Metformin make you lose weight?

Research shows that metformin helps people lose weight. However, it’s not clear how metformin causes weight loss. One of the proposed theories is that it may reduce your appetite. People who follow a healthy diet and exercise while taking metformin tends to lose more weight.

Is Metformin dangerous?

Generally, metformin is not dangerous, but prolonged use of metformin or using metformin with alcohol or some other drugs may cause a serious condition called lactic acidosis, a buildup of lactic acid in the blood that can be fatal.

Is metformin bad for the kidneys?

No, generally metformin is safe and doesn’t affect kidneys. However, it should not be used along with alcohol or in people suffering with kidney function impairment as it can cause a severe condition known as Lactic acidosis which can be fatal.

Do you take Metformin before or after a meal?

Metformin should be taken along with meals, if you miss to take along with meals then take it immediately after meals to prevent stomach or bowel irritation that may occur during the first few weeks of using metformin. Do not crush, break, or chew the extended-release tablet. Swallow the whole tablet with a full glass of water.

Why you should not take Metformin?

Metformin can cause a severe condition called lactic acidosis. People who have lactic acidosis have a buildup of lactic acid in their blood and shouldn’t take metformin. So, you must follow your doctor’s advice before starting or while using metformin.

Can I drink alcohol while taking Metformin?

People who frequently drink alcohol or drink a lot in a short time are at much higher risk of developing serious side effects. These effects include hypoglycemia (reduced blood sugar level), and a condition called lactic acidosis. This buildup of lactic acid can cause severe damage to your kidneys, lungs, heart and blood vessels. If lactic acidosis is not treated immediately, it can cause these organs to shut down, which can be fatal.

What is lactic acidosis?

Lactic acidosis is a rare, but severe side effect of metformin. This condition is caused due to the buildup of lactic acid in your blood. Your body produces lactic acid as a result of utilizing energy. When you use metformin, your body produces more lactic acid than it usually does.

What are the symptoms of lactic acidosis?

Lactic acidosis symptoms include weakness, tiredness, dizziness, lightheadedness, unusual muscle pain, such as sudden and severe pain in muscles that don’t usually cramp, stomach discomfort, nausea, cramping, such as a fluttering feeling, trouble breathing, or sharp pains, and feeling cold.

Can metformin make you put on weight?

No, in fact, metformin helps to lose weight and is used off-label to treat women with PCOS and overweight and it regulates hormones in women and helps to get pregnant. However, when you suddenly stop using metformin after using it for a long time, this can lead to weight gain. Your doctor may reduce the dose gradually with proper diet before discontinuing the use of metformin.

Does metformin make you gain weight or lose weight?

Metformin helps to lose weight and is used off-label to treat women with overweight and PCOS. However, without following healthy diet habits may not lead to weight loss. People who follow a healthy diet and exercise while taking metformin tend to lose more weight.

What are the best fruits to eat for diabetics?

Generally, fruits do not raise blood sugar level when taken in moderation as fruits contain fructose. However, consider citrus fruits, pineapple, papaya, cantaloupe, apricots, grapes, apples, berries are healthy fruits in a diabetes diet. Have a whole fruit instead of fruit juices.

Is Metformin good for PCOS?

Yes, metformin helps to maintain regular menstrual cycle and lowers body mass index (BMI), luteinizing hormone (LH) and testosterone, within six months of treatment in women with polycystic ovary syndrome (PCOS) and helps to get pregnant.

Can I use metformin in PCOS?

Yes, your doctor may prescribe you metformin for the treatment of PCOS in women as it can enhance ovulation and regulate menstrual cycles. However, avoid self-medication.

Does metformin make you lose weight with PCOS?

Yes, metformin is an anti-diabetes drug that helps the body to utilise insulin more efficiently. Research has found that metformin helps obese women with PCOS lose weight.

How Long Should metformin be taken for PCOS?

The duration of treatment is not known. Women with PCOS higher risk of developing diabetes in later life. A dose of 500mg three times per day or 850mg twice daily is often prescribed.

Can metformin help you get pregnant with PCOS?

Yes, metformin helps to maintain regular menstrual cycle and lowers body mass index (BMI), luteinizing hormone (LH) and testosterone, within six months of treatment in women with polycystic ovary syndrome (PCOS) and helps to get pregnant. However, not all women with polycystic ovary syndrome have good results.


TheMedPharma has made every effort to make sure that all the information is factually correct, comprehensive, and up-to-date. However, this website should not be considered as a substitute for the advice, knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or licensed health care professional before taking any medication. The drug information contained herein is subjected to changes if required. The lack of warnings or other information for a given drug does not mean that the drug or its combination is safe, effective or appropriate for use in all patients.