Methadone facts

What is Methadone?

Effects of methadone

Tolerance and dependence

Getting help

Methadone use in Australia

Please note: The information given on this page does not constitute medical advice and should not be relied upon in this way. The information is correct at the time of publication. People wanting medical advice on this issue should consult a doctor.

What is methadone?

Methadone belongs to the group of drugs known as opioids.

Opioids are classed as depressant drugs as they work by slowing down the functions of the central nervous system. Alcohol, cannabis and benzodiazepines are examples of other depressant drugs.

Methadone is manufactured and is used as a substitute for the treatment of people dependent on heroin and other opioids.

Its effects are much longer lasting than heroin, a single dose being effective for approximately 24 hours; the effects of heroin may only last for a couple of hours.

In a treatment program, methadone is usually given out in syrup form and drunk with cordial or fruit juice.

Other names

“done” or “the done”

What it looks like

Methadone comes as a tablet, syrup or injection.

How is it used?

Generally, there are two types of methadone programs:

  • Maintenance or long-term programs. These may last for months or years, and aim to reduce the harms associated with drug use and improve quality of life.
  • Withdrawal (short-term) detoxification programs. These last approximately 5–14 days, and aim to ease the discomfort of coming off heroin.

Effects of methadone

The effects of any drug (including methadone) vary from person to person. How methadone affects a person depends on many things including their size, weight and health, also whether the person is used to taking it and whether other drugs are taken around the same time. The effects of any drug also depend on the amount taken.

Some people on methadone programs will experience unwanted symptoms during their treatment. These may be caused by the dosage they are receiving being too low or too high, which can occur particularly at the beginning of treatment. Some symptoms may also occur due to the side effects of the drug itself.

There is no safe level of drug use. Use of any drug always carries some risk—even medications can produce unwanted side effects. It is important to be careful when taking any type of drug.

Low dose

Symptoms of a methadone dose being too low may resemble having a bout of flu. They include:

  • runny nose, sneezing
  • abdominal cramps
  • feeling physically weak
  • loss of appetite
  • tremors
  • muscle spasms and jerking
  • goose bumps
  • tears
  • nausea/vomiting
  • yawning
  • diarrhoea
  • back and joint aches
  • high temperature but feeling cold
  • sweating
  • irritability, aggression, feelings of uneasiness
  • difficulty sleeping
  • cravings for the drug.

A person who suddenly stops taking methadone may experience many of the symptoms listed above. The withdrawal symptoms usually begin 1 to 3 days after the last dose, and peak around the 6th day, but can last longer.

High dose

Symptoms of too high a dose include:

  • drowsiness, nodding off
  • nausea, vomiting
  • shallow breathing
  • pinpoint pupils
  • low body temperatures
  • slow pulse
  • lowered blood pressure
  • heart palpitations
  • dizziness
  • problems with sexual functioning
  • poor blood circulation.

Other side effects

Some people may also experience certain side effects that are unrelated to the dosage, including:

  • sweating (clients should drink at least two litres of water per day to avoid dehydration)
  • constipation
  • aching muscles and joints
  • lowered sex drive
  • skin rashes and itching
  • sedation
  • fluid retention
  • loss of appetite, nausea, vomiting
  • abdominal cramps
  • tooth decay
  • irregular periods.

Side effects should decrease soon after the methadone program is completed. As with all opiates, methadone alone in its pure form will not cause any damage to the major organs of the body. Prolonged use will not cause any physical damage, apart from tooth decay.

For those with pre-existing impaired liver function (following conditions such as hepatitis B, hepatitis C infection, or prolonged alcohol use), the methadone dose may require careful monitoring.

People who are not dependent on opiates who take methadone will experience some of the short-term effects similar to those on a methadone program receiving too high a dose.

Other effects of methadone use

Taking methadone with other drugs

Deaths related to methadone only are rare. Methadone-related deaths are usually due to combining methadone with other drugs, particularly benzodiazepines and alcohol. Dealing with a methadone overdose.

Pregnancy and breastfeeding

Read about the effects of taking drugs during pregnancy or breastfeeding.


It is dangerous to drive after using methadone. The effects of methadone, such as sedation, can affect driving ability.

Read more about the effects of drugs on driving.

Methadone use in the workplace

Under occupational health and safety legislation, all employees have a responsibility to make sure they look after their own and their co-workers’ safety. The effects of methadone such as drowsiness and sedation can affect a person’s ability to work safely and effectively.

Tolerance and dependence

People who use methadone regularly for a prolonged period can develop dependence and tolerance to it, which means they need to take more methadone to get the effect they are used to having.

Dependence on methadone can be psychological, physical, or both. They crave the drug and find it very difficult to stop using it. Physical dependence occurs when a person’s body adapts to methadone and gets used to functioning with the methadone present.

Getting help


In Australia, there are many different types of treatments for drug problems. Some aim to help a person to stop using a drug, while others aim to reduce the risks and harm related to their drug use. Find out more about treatment.

What to do if you are concerned about someone’s methadone use

If you are concerned about someone’s drug use, there is help available. Contact the alcohol and drug information service in your state or territory.

What to do in a crisis

Always call triple zero (000) if a drug overdose is known or suspected—and remember that paramedics are not obliged to involve the police.

If someone overdoses or has an adverse reaction while using methadone, it is very important that they receive professional help as soon as possible. A quick response can save their life.

Visit the Better Health Channel to read St John Ambulance’s advice on drug overdose.

Methadone use in Australia

According to National Opioid Pharmacotherapy Statistics Annual Data collection [PDF: 709KB] (new window), in 2009, approximately 30,000 Australians were undertaking methadone treatment.

    For more statistics about the use of methadone in Australia, visit our statistics

National drug policy

Australia’s national drug policy is based on harm minimisation. Strategies to minimise harm include encouraging people to avoid using a drug, through to helping people to reduce the risk of harm if they do use a drug. It aims to reduce all types of drug-related harm to both the individual and the community.