What Is Australia's Most Dangerous Drug? The Answer Isn't What Most People Think (Part 1)

sameboatadmin · July 30, 2026, 10:42am

This article is part of a four-part series exploring Australia’s changing drug landscape, looking at which substances cause the most harm, who is affected, and how Australia is responding. Read the full series:

Part 1 | You are here
Part 2 | Methamphetamine, Cocaine and Australia’s Changing Drug Landscape
Part 3 | The Deadliest Drugs in Australia: Overdose, Opioids and Regional Differences
Part 4 | How Australia’s Drug Landscape Has Changed — And Where It May Be Heading

When people hear the words dangerous drug, many immediately think of methamphetamine (“ice”), heroin, or fentanyl. News headlines often focus on dramatic police raids, overdose deaths, or organised crime, creating the impression that one drug stands above all others as Australia’s biggest problem.

The reality is far more complex.

There is no single “most dangerous” drug. The answer depends entirely on how we measure harm. Is the most dangerous drug the one used by the greatest number of people? The one responsible for the most deaths? The most addictive? Or the one that causes the greatest harm to families, communities and emergency services?

Each of these questions has a different answer.

Australia’s experience with illicit drugs has changed significantly over the past two decades. While cannabis remains by far the most commonly used illegal drug, methamphetamine continues to have a disproportionate impact on crime, mental health and community safety. Cocaine use has increased steadily in many parts of the country, while opioid overdoses remain one of the leading causes of drug-related deaths.

Understanding these differences matters because public discussion often focuses on the drugs making headlines rather than those causing the greatest overall harm.

This article examines the latest Australian evidence to answer a simple question:

Which drug is actually Australia’s most dangerous?

The answer may surprise you.

What Does “Most Dangerous” Actually Mean?

Imagine two fictional drugs.

Drug A is used by two million Australians every year. Most users experience relatively minor short-term harm, but because so many people use it, it creates a large overall burden on the health system.
Drug B is used by only 40,000 people. However, it has a very high risk of addiction, overdose, violence and long-term health problems.

Which one is more dangerous?

There isn’t a single correct answer.

Researchers generally assess drugs using several different measures rather than relying on one statistic. These include:

Number of users

How many Australians use the drug each year?

A drug used by millions of people is likely to create more total health impacts than one used by only a few thousand.

Addiction potential

Some drugs create dependence much more quickly than others. Addiction can affect employment, relationships, finances and physical and mental health, making it one of the most important measures of harm.

Risk of overdose

Certain drugs carry a much greater risk of fatal overdose, particularly opioids and combinations of multiple substances.

Long-term health effects

Different drugs affect the body in different ways. Some primarily affect the lungs, others the brain, heart or liver. Long-term use can increase the risk of chronic disease, mental illness and cognitive impairment.

Harm to families and communities

Drug use does not affect only the individual.

Some substances are associated with increased family conflict, child neglect, road trauma, workplace injuries, crime and greater demand on police, ambulance and hospital services.

This broader social impact is one reason why governments often prioritise particular drugs even when they are used by relatively few people.

Photo by Wesley Gibbs on Unsplash

Australia’s Most Commonly Used Illegal Drugs

Contrary to what many people assume, methamphetamine is not Australia’s most widely used illicit drug.

That distinction belongs to cannabis, and by a considerable margin.

Recent national surveys consistently show cannabis remains Australia’s most commonly used illegal drug, followed by cocaine, while methamphetamine is used by a much smaller proportion of the population.

Although exact numbers vary slightly between survey years, the overall picture has remained remarkably consistent.

Illegal drug	General trend in Australia
Cannabis	Most commonly used illegal drug
Cocaine	Second most commonly used and increasing
Hallucinogens	Growing in popularity, particularly among younger adults
Ketamine	Increasing from a relatively small base
MDMA (Ecstasy)	Declined during COVID-19 before recovering
Methamphetamine	Lower prevalence than cannabis but higher rates of severe harm
Heroin	Relatively uncommon compared with the 1990s

One of the most interesting findings from recent national surveys is that Australia’s drug market has become increasingly diverse.

Twenty years ago, discussions about illicit drugs often focused on cannabis, heroin and amphetamines. Today, Australians are more likely to encounter cocaine, ketamine, psychedelic substances and a growing range of synthetic drugs.

These changing patterns present new challenges for health professionals and policymakers, particularly because different drugs carry different risks and require different approaches to prevention and treatment.

The Drug Most Australians Use: Cannabis

If popularity alone determined danger, cannabis would rank first. Millions of Australians report using cannabis, making it by far the country’s most commonly consumed illicit drug. Several factors contribute to its widespread use.

Changing community attitudes have reduced some of the stigma surrounding cannabis. Medical cannabis has become increasingly available for specific health conditions, and discussions about legalisation in Australia and overseas have influenced public perceptions.

However, widespread use should not be confused with harmlessness.

While many people use cannabis without experiencing serious immediate consequences, regular or heavy use can increase the risk of dependence, impaired memory and concentration, reduced motivation, respiratory problems when smoked, and mental health complications for some individuals—particularly those with a personal or family history of psychotic illness.

Young people are especially vulnerable because the brain continues to develop into the mid-twenties. Frequent cannabis use during adolescence has been associated with poorer educational outcomes and an increased likelihood of developing dependence later in life.

Even so, cannabis is relatively uncommon as a direct cause of fatal overdose. This distinguishes it from opioids and several other illicit drugs.

In other words, cannabis reaches the greatest number of Australians, but it is not the drug responsible for the greatest number of deaths or the greatest level of community harm.

Why Methamphetamine Dominates Public Discussion

If cannabis is Australia’s most common illicit drug, why does methamphetamine receive so much more media attention?

The answer lies in the type of harm it causes.

Methamphetamine—particularly its crystalline form known as ice—is associated with a much higher likelihood of severe dependence than many other illicit drugs. It stimulates the central nervous system, producing intense feelings of energy, confidence and alertness that can last for many hours.

Repeated use places enormous strain on both the brain and the body.

People experiencing severe methamphetamine dependence may develop anxiety, paranoia, sleep deprivation and, in some cases, stimulant-induced psychosis. These effects can place users and those around them at greater risk of harm, especially when treatment is delayed.

It is important to avoid stereotypes. The overwhelming majority of people who use methamphetamine are not violent, and sensational media portrayals can discourage people from seeking help.

However, health services, police and emergency departments consistently report that methamphetamine contributes disproportionately to high-risk incidents requiring urgent intervention.

For this reason, many experts consider methamphetamine one of Australia’s most harmful illicit drugs—not because the largest number of people use it, but because of the severity of the harm experienced by a relatively small proportion of users.

At first glance, this may seem contradictory.

Cannabis has the most users.

Methamphetamine causes some of the greatest community harm.

Opioids are responsible for many of the country’s fatal overdoses.

So which drug deserves to be called Australia’s most dangerous?

The answer becomes clearer when we look beyond prevalence and examine addiction, overdose risk, and the impact each drug has on Australian families and communities.