"Legal high" facts

What are "legal highs"?

Effects of "legal highs"

Tolerance and dependence

Getting help

"Legal high" use in Australia

What are "legal highs"?

"Legal highs" is a general term for substances that are designed to mimic or produce similar effects to common illicit drugs such as cocaine, ecstasy and cannabis.

Please note: Although these drugs are often called "legal highs", some of these substances are actually illegal in Australia.
(See below Are they really legal?)

"Legal highs" have different chemical structures to the illicit substances that they are trying to mimic, so they can be marketed as "legal" and a safe and acceptable alternative to illicit drugs; however, this is not the case.

It is not known how safe they really are as there is limited research on the short-, medium- and long-term effects of these substances. There are also concerns about what is actually in "legal highs". There are not always quality control checks on "legal highs", so it is not always known what substances they contain.

The three most common types of "legal highs" are:

"Herbal highs" and "party pills"

"Herbal highs", also known as "party pills", are often marketed as herbal supplements that offer increased energy or mood with similar effects to stimulants such as ecstasy or amphetamines.

In Australia until 2009, "herbal highs" were primarily based on two ingredients, BZP (benzylpiperazine) and TFMPP (triflouro-methyl-phenylpiperazine). Other ingredients included piper nigrum, phenylalanine, tryptophan and tyrosine.

The most common ingredients in the new BZP-free "herbal highs" are caffeine, citrus aurantium and geranamine (geranium extract).

What do they look like?

"Herbal highs" are available as pills or as small bottles of liquid.

Research chemicals can come in the form of powders, crystals or capsules in a variety of colours.

How are they used?

They are generally swallowed.

Synthetic cannabinoids

Synthetic cannabinoids are man-made chemicals that are similar to delta-9 tetrahydrocannabinol (THC), the active ingredient in cannabis. Synthetic cannabinoids are usually sold combined with herbs and aim to mimic the effects of cannabis

"Spice" was the earliest in a series of synthetic cannabinoids sold in Australia. Since then a number of other similar products have been developed for sale such as "Kronic".

What do they look like?

Synthetic cannabinoids look like dried herbs.

How are they used?

They are generally smoked or occasionally drunk as a tea.

Research chemicals and drug analogues

In an attempt to avoid legislative controls, some producers and suppliers are now manufacturing illicit drug analogues and derivatives.

Drug analogues are substances that are chemically similar to other drugs. Drug derivatives are substances that are made from another drug. These drug analogues or derivatives often belong to various groups of drugs such as cathinones, phenethylamines and tryptamines. The most commonly known is mephedrone.

Labelling on these products can be deceptive, with some described as "research chemicals", "plant food" or "bath salts". They also include warnings such as "Not for human consumption" or "Only for research purposes".

What do they look like?

Research chemicals usually come as a white powder, crystals or capsules. Anecdotal reports indicate that they are most commonly sold as a powder with a yellowish tinge.

How are they used?

These substances may be swallowed, smoked, injected, snorted or taken anally ("shelved").

Effects of "legal highs"

The effects of any drug, including "legal highs", vary from person to person. How "legal highs" affect 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.

It can be hard to judge how much of a "legal high" has been taken, as they are not regulated, so quality and strength will vary from one batch to another.

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.

"Legal highs" generally aim to mimic the effects of illicit drugs such as ecstasy, cocaine, amphetamines and cannabis. These may include:

  • increased energy and alertness
  • elevated mood
  • feelings of relaxation and sedation.

There is varying anecdotal evidence of the effectiveness of "legal highs" in mimicking the effects of illegal drugs. Only limited research is available on the effects, short and long-term, of "legal highs".

People who have used synthetic cannabinoids have reported negative effects such as:

  • paranoia
  • anxiety
  • racing thoughts
  • irritability.

Less commonly reported negative effects include:

  • hallucinations
  • tremors
  • seizures
  • drowsiness
  • slurred speech
  • increased blood pressure
  • vomiting
  • chest pain.

The smoking of any substance is likely to have a harmful effect on health, in the same way that smoking tobacco puts people at risk of developing conditions such as chronic bronchitis and lung cancer.

Other effects of "legal highs"

Social problems

All areas of a person's life can be affected by drug use. Disagreements and frustration over drug use can cause family arguments and affect personal relationships. Legal and health problems can also add to the strain on personal, financial and work relationships.

Taking legal highs with other drugs

The effects of any drug can be unpredictable but even more so when it comes to mixing different substances. Mixing drugs is also the most common cause of overdose.

Pregnancy and breastfeeding

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


It is dangerous to drive after taking any drug, including "legal highs". The effects of drugs can affect driving ability, increasing the chance of an accident.

Read more about the effects of drugs on safe driving.

Legal highs and 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 drugs, including "legal highs", can affect a person's ability to work safely and effectively.

Read more about alcohol and other drugs in the workplace.

Preventing and reducing harms

The use of any drug carries a risk of harm. This risk is increased when:

  • large amounts are taken
  • it is taken with other drugs, including alcohol, and prescribed and over-the-counter medications
  • it is snorted (due to the risk of damage to the lining of the nose)
  • it is injected (due to the risks of vein damage and of contracting bloodborne viruses)
  • the person who takes the drug is alone (as they may need help in a medical emergency)
  • the person who takes the drug drives or operates machinery while under its influence.

Tolerance and dependence

Many drugs are addictive after prolonged use. People who use a drug regularly can develop tolerance to it. This means they need to take larger amounts of the drug to get the same effect. People who are dependent on the drug find that using the drug becomes far more important than other activities in their life. They crave the drug and find it very difficult to stop using it.

Getting help

In Australia, there are many different treatment options for drug problems. Some aim to help a person stop using a drug, while others aim to reduce the risks and harm related to their drug use.

Read more about treatment.

What to do if you are concerned about someone's "legal high" 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 legal highs, 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.

"Legal high" use in Australia

There are no authoritative statistics available regarding the use of "legal highs" in Australia.

Are they really legal?

While "legal highs" are marketed as legal substances, concerns about their safety have led to a number of controls being placed upon them.

As of 8 July 2011, the Commonwealth of Australia has placed eight synthetic cannabinoids under Schedule 9 (Prohibited Substances) of the Poisons Standard.

Prohibited Substances under Schedule 9 are poisons and preparations whose sale, distribution, use, possession and manufacture is prohibited and they may be used only for medical and scientific research.

Victoria automatically adopts the schedules of the Poisons Standard, so these 8 synthetic cannabiniods and their derivatives were:

  • controlled as Schedule 9 poisons under the Victorian Drugs Poisons and Controlled Substances Act 1981.
  • listed as drugs of dependence.

Mephedrone is also a Schedule 9 poison (Prohibited substance) in Victoria. It has been added to Schedule 4 of the Customs (Prohibited imports) Regulations 1956, meaning that it can only be imported into Australia with a valid licence and permit.

Read more about drugs and Australian law.

For legal advice specific to your situation contact a legal aid service in your state or territory.

Back to "What are legal highs?"

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.


DrugInfo 2010 Mephedrone facts, West Melbourne: ADF

Hillebrand J, Olszewski D & Sedefov R 2010 Legal Highs on the Internet, Lisbon: EMCDDA

National Cannabis Information Centre n.d. Spice fact sheet, Canberra: NCPIC, 29 October 2011

Reuter P 2011 Options for regulating new psychoactive drugs: a review of recent experiences, London: UK Drug Policy Commission

European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) 2010 Understanding the 'Spice' phenomenon, Lisbon: EMCDDA

Psychonaut Web Mapping Research Group 2010 Psychonaut Web Mapping Project: Final report, London: Institute of Psychiatry, King’s College

Australian Customs and Border Protection Service 2010 "Legal Highs" Not necessarily legal [PDF: 893KB](new window), Canberra: Australian Government

Birdwell J, Chapman J & Singleton N 2011 Taking drugs seriously – a Demos and UK Policy Commission report on legal highs [PDF: 653KB](new window), London: Demos

Zimmermann U, Winkelmann P, Pilhatsch M, Nees J, Spanagel R & Schulz K 2009
"Withdrawal phenomena and dependence syndrome after the consumption of 'Spice Gold'", Deutsches Ärzteblatt, 106:27, pp. 464–7