Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content


2-minute read

Metformin is commonly prescribed for managing type 2 diabetes. To get metformin, you need to have a prescription written for you by your doctor.

Looking for a medicine?

Visit healthdirect’s list of medicines that contain metformin to find out more about a specific medicine.

On this page you will find more information on what metformin is, what it’s used for, how it works, its risks and whether there are any other treatment options available in its place.

What is metformin?

Metformin hydrochloride is a diabetes medicine.

What is metformin used for?

Metformin is used to control blood glucose (sugar) levels in people who have type 2 diabetes. It can be prescribed for adults and children over the age of 10.

Because metformin doesn’t cause weight gain and may help with weight loss, it is commonly prescribed for overweight people with type 2 diabetes.

In adults, metformin can be used alone or together with other diabetes medicines, including insulin.

How does metformin work?

Metformin lowers blood glucose levels in two ways, by:

  • reducing how much glucose is released from the liver, where it is stored
  • helping the cells of your body to absorb more glucose from the bloodstream

What forms of metformin are available?

Metformin is available in different:

  • brands
  • packaging
  • forms like tablets, extended release tables or combined with other diabetes medicines in the same tablet
  • strengths.

Risks and benefits of metformin

Metformin reduces the complications caused by diabetes. Among its benefits are that it:

  • doesn’t cause weight gain
  • reduces bad cholesterol
  • is very unlikely to cause abnormally low blood glucose levels (hypoglycaemia).

Common gastrointestinal side effects of metformin include:

  • diarrhoea
  • nausea
  • vomiting
  • stomach upset, cramps and bloating.

Each person responds to medicines differently. Just because a side effect is listed does not mean you will experience it.

This is not a full list of side effects. For more information, read the Consumer Medicines Information (CMI) for the brand of metformin you are taking, or talk to your doctor or pharmacist.

If you are experiencing a serious or life-threatening side effect, immediately dial triple zero (000).

Alternatives to metformin

Usually, metformin is the first choice of medicine prescribed by doctors for type 2 diabetes, when lifestyle changes of diet and exercise have failed. If metformin no longer works well enough on its own, your doctor may add another diabetes medicine to metformin. But if metformin is not suitable for you, your doctor may prescribe you another diabetes medicine altogether.

This page does not give you all the available information about metformin. Please read the CMI for the brand of metformin prescribed, and ask your doctor or pharmacist the important questions.

Last reviewed: December 2016

Need more information?

These trusted information partners have more on this topic.

Top results

Medicines and type 2 diabetes | NPS MedicineWise

Type 2 diabetes may be treated with drugs such as metformin, sulfonylureas & insulin. Read about diabetes medicines & how to manage them.

Read more on NPS MedicineWise website

Current year alerts | Therapeutic Goods Administration (TGA)


Read more on TGA – Therapeutic Goods Administration website


Tablets Medication for type 2 diabetes People with type 2 diabetes are often given medications including insulin to help manager their blood glucose levels

Read more on Diabetes Australia website


Tablets There are five classes of tablets currently used in Australia for lowering blood glucose levels for people with type 2 diabetes

Read more on Diabetes Australia website

Polycystic ovarian syndrome (PCOS) information | myVMC

Polycystic ovarian syndrome refers to increased levels of androgens (primary male hormones) and menstrual irregularities in women.

Read more on myVMC – Virtual Medical Centre website

Iodine-containing contrast medium - InsideRadiology


Read more on InsideRadiology website

Taking medications - ANZCA

Read more on ANZCA – Australian and New Zealand College of Anaesthetists website

Infertility treatment | Jean Hailes

There are many reasons a woman may have difficulty becoming pregnant. There are a number of things you can do to increase the likelihood of becoming pregnant including lifestyle changes, surgery, hormone treatment and Assisted Reproductive Technology

Read more on Jean Hailes for Women's Health website

Fatty liver disease (NAFLD) information video | myVMC

Non-alcoholic fatty liver disease (NAFLD) is an accumulation of fatty deposits in the liver, causing cirrhosis. It is diagnosed by liver function tests.

Read more on myVMC – Virtual Medical Centre website

PCOS | Jean Hailes

Polycystic ovary syndrome (PCOS) affects 12-18% of women of reproductive age and up to 21% in some high-risk groups, such as Indigenous women.

Read more on Jean Hailes for Women's Health website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Government of Western Australia, health department logo