What are psychedelics?

Psychedelics (also known as hallucinogens) are a class of psychoactive substances that produce changes in perception, mood and cognitive processes.1

Psychedelics affect all the senses, altering a person’s thinking, sense of time and emotions. They can also cause a person to hallucinate—seeing or hearing things that do not exist or are distorted.1

Commonly used psychedelics

Explore psychedelics on the Drug Wheel

Drug Wheel psychedelics

View the Drug Wheel

Psychedelics - How drugs affect you

Psychedelics: How drugs affect you (bundle of 50)


$36.32 (inc. GST)

View in ADF Shop

What do psychedelics look like?

There are many different kinds of psychedelics. Some occur naturally, in trees, vines, seeds, fungi and leaves. Others are made in laboratories.2 They come in many forms including tablets, blotter paper, dried mushrooms, powders and crystalline powders.

Types of psychedelics

  • LSD (Lysergic acid diethylamide) is made from a substance found in ergot, which is a fungus that infects rye.3
  • Psilocybin is a naturally occurring substance found in mushrooms and is found in many parts of the world.4
  • Mescaline is derived from the Mexican peyote and San Pedro cactus and produces similar effects to LSD.5
  • DMT (Diemethyltryptamine) is structurally similar to psilocin, an alkaloid found in psilocybin mushrooms. It can be synthesised in the laboratory but is also a naturally occurring component of several plants.4
  • 2C-B (4-Bromo-2,5-dimethoxyphenethylamine) is a psychedelic drug first synthesised in 1974. 2C-B is considered both a psychedelic and a mild entactogenic. ‘Entactogen’ means ‘touching within’ and is a term used by psychiatrists to classify MDMA and related drugs.6
  • Peyote (Lophophora williamsii) is the most well-known and potent psychedelic cactus, although the smallest and slowest growing. Instead of growing upward to form a column, it grows as ‘buttons’ low to the ground. It has been used by Native Americans for over 5000 years.5
  • 25[-x]-NBOMe (N-methoxybenzyl) is the name for a series of drugs that have psychedelics effects. Reports indicate that there are a number of different versions of NBOMe available – all with differing effects.7

How are they used?

Psychedelics have been used since ancient times by various cultures throughout the world for their mystical and spiritual associations. LSD, magic mushrooms, Mescaline and DMT are usually swallowed, smoked or inhaled. Mushrooms are usually eaten fresh, cooked or brewed into a ‘tea’.

Occasionally, they may be mixed with tobacco or cannabis and smoked. Mescaline is usually swallowed. Peyote buttons may be ground into a powder and smoked with cannabis or tobacco. The buttons can also be chewed or soaked in water to produce a liquid.

Most forms of NBOMe are inactive if swallowed, and the most common methods of taking them are under the tongue, held in the cheek or snorted.

Generally, people who use psychedelics don’t take them on a regular basis, but on occasions that may be weeks or months apart.

Effects of psychedelics

There is no safe level of drug use. Use of any drug always carries some risk. It’s important to be careful when taking any type of drug.

Psychedelics affect everyone differently, based on:

  • size, weight and health
  • whether the person is used to taking it
  • whether other drugs are taken around the same time
  • the amount taken
  • the strength of the drug (varies from batch to batch)
  • environment (where the drug is taken).

The effects of psychedelics can last several hours and vary a lot, depending on the type of psychedelic used.

  • feelings of euphoria
  • sense of relaxation and wellbeing
  • seeing and hearing things that aren’t there
  • confusion and trouble concentrating
  • dizziness
  • blurred vision
  • clumsiness
  • fast or irregular heart beat
  • breathing quickly
  • vomiting
  • sweating and chills
  • numbness.6,7

Impact of mood and environment

Drugs that affect a person’s mental state (psychoactive drugs) can also have varied effects depending on a person’s mood (often called the ‘set’) or the environment they are in (the ‘setting’).

Set: a person’s state of mind, previous encounters with psychedelic drugs, and expectations of what’s going to happen. For example, feelings of stress or anxiety before using psychedelic drugs may result in an unpleasant experience (bad trip).9

Setting: the environment in which someone consumes psychedelic drugs – whether it’s known and familiar, who they’re with, if they’re indoors or outdoors, the type of music and light. For example, using psychedelics in a calm, quiet and relaxed environment can lead to, or contribute to, a pleasant experience but being in a noisy, crowded place may result in a negative experience.9

Being in a good state of mind, with trusted friends and a safe environment before taking psychedelics reduces the risk of having a bad trip.

Bad trips

Sometimes you can experience a ‘bad trip’, which is frightening and disturbing hallucinations. This can lead to panic and unpredictable behaviour, like running across a road or attempting suicide.

If you take a large amount or have a strong batch, you are likely to experience negative effects of psychedelics.3,9


The most common long-term effect of psychedelic use is the ‘flashback’. Flashbacks are a re-experience of the drug and can occur days, weeks, months and even years later.

Flashbacks can be triggered by the use of other drugs or by stress, fatigue or physical exercise. The flashback experience can range from being pleasant to causing severe feelings of anxiety. They are usually visual and last for a minute or two.3,9

Mixing psychedelics with other drugs

The effects of mixing psychedelics with other drugs, including alcohol, prescription medications and over-the-counter medicines, are often unpredictable.

Mixing psychedelics with stimulant drugs increases the stimulant effect and can further increase heart rate and place the body under extreme stress. Stimulants can also increase anxiety which can lead to a negative experience.10

Mixing psychedelics with benzodiazepines can increase anxiety, sadness and rapid heart rate.11

More on Polydrug use

‘Polydrug use’ is a term for the use of more than one drug or type of drug at the same time or one after another.1 Polydrug use can involve both illicit drugs and legal substances, such as alcohol and medications.


Reducing harm

Use of any drug always carries some risk. 

If you do decide to use psychedelics, it’s important to consider:

  • it’s difficult to predict the strength and effects of psychedelics (even if they have been taken before), as the strength and potency can vary from batch to batch
  • people with mental health conditions or a family history of these conditions should avoid using psychedelics
  • taking psychedelics in a familiar environment in the company of people who are known and trusted may alleviate any unpleasant emotional effects. Anxiety can be counteracted by taking deep, regular breaths while sitting down.

Using psychedelics is likely to be more dangerous when:

  • taken in combination with alcohol or other drugs, particularly stimulants such as crystal methamphetamine (‘ice’) or ecstasy
  • driving or operating heavy machinery
  • judgment or motor coordination is required
  • alone (in case medical assistance is required)
  • the person has mental health issues.

Dependence and tolerance

Most psychedelics produce tolerance quickly, meaning you need to take larger doses to get the same effect. Psychological dependence can happen for some people.

It’s not likely you can become physically dependent on psychedelics. There are no withdrawal symptoms even after using them for a long time.

Getting help

If your use of psychedelics is affecting your health, family, relationships, work, school, financial or other life situations, or you’re concerned about a loved one, you can find help and support.

  • Call DrugInfo on 1300 85 85 84 or email druginfo@adf.org.au to speak to a real person and your questions answered as well as advice on practical ‘next steps’. It’s confidential too.
  • Help and Support Services search
    Find a service in your local area from our list. Simply add your location or postcode and filter by service type to quickly discover help near you.

Polydrug use

What is polydrug use?

‘Polydrug use’ is a term for the use of more than one drug or type of drug at the same time or one after another.1 Polydrug use can involve both illicit drugs and legal substances, such as alcohol and medications.

Other names

Multiple drug use, multiple substance use

Multiple drugs

Reasons for mixing drugs

There are many reasons people mix drugs, this might include:

  • to ‘bring’ on or enhance the desired effects of one drug, such as drinking alcohol while using stimulants
  • to stop or decrease the negative effects of a drug, such as using depressants like cannabis or benzodiazepines to reduce the impact of coming down from stimulants
  • substituting a drug of choice for an alternative; for example, being unable to access heroin and substituting it with alcohol and cannabis instead
  • when a person is intoxicated by alcohol or other drugs and they take another drug without thinking about or considering the effects
  • to reduce dependence on one drug by using a combination of others.2

Effects of polydrug use

There is no safe level of drug use. Use of any drug always carries some risk. It is important to be careful when taking any type of drug.

Polydrug use may affect everyone differently, based on:

  • size, weight and health
  • whether the person is used to taking the combination of drugs
  • the amounts taken
  • the strength of the drugs (varies from batch to batch for each illegally produced drug)
  • if alcohol or medications are consumed as well.

It is difficult to predict the effects of one drug, but it is even harder to predict the effects of multiple drugs.

Taking multiple drugs of the same class (such as two stimulants) increases the impact on the brain and body and overdose can occur.3

Effects become even more complicated to predict if different classes of drugs are taken. For example, taking a stimulant with a depressant.3

Any drugs taken in combination increase the risk of harm.

Mixing stimulants

When different stimulants are taken at the same time, such as cocaine and ice, the possibility of heart problems increases. Combining stimulants also increases the risk of psychosis, anxiety, or panic attacks. The likelihood of experiencing serotonin syndrome is also increased.3

Serotonin syndrome

Serotonin is a hormone found in the brain that controls our mood, feelings of well-being and happiness.4 Serotonin syndrome is a harmful drug reaction caused by too much serotonin and is often linked to MDMA, methamphetamine and cocaine. It can be fatal.

Mild side effects can include:

  • mental confusion
  • hyperactivity
  • muscular problems.5

More serious side effects can include:

  • fever and sweating
  • rapid heartbeat
  • muscle spasms5
  • death.

Mixing depressants

Depressant drugs slow down the activity of the central nervous system and reduce breathing rate.

When two or more depressants are combined there is an increased risk of:

  • accidents or injury
  • impaired judgement and coordination
  • vomiting
  • irregular or shallow breathing
  • blackouts and memory loss
  • unconsciousness
  • coma
  • death.6

Mixing depressants and stimulants

If stimulants are mixed with depressants the body is placed under a lot of stress as it tries to deal with the competing effects.

For example, when methamphetamine is combined with alcohol the heart experiences greater strain. This can lead to dangerous complications, particularly for someone with a heart condition.

Other effects of combining depressants and stimulants include:

  • heart problems
  • respiratory infections and bronchitis
  • dehydration, overheating, and kidney failure.3

Mixing medications

Mixing medications, either prescribed or over-the-counter, with other drugs can have negative effects.

Combining benzodiazepines with opioids can lead to a decreased breathing rate and an increased risk of overdose.7

Some pharmaceutical drugs, such as strong pain relievers, antidepressants, anticonvulsants, anti-psychotics, some antihistamines and over-the-counter medications, can have an adverse effect when taken with benzodiazepines, leading to breathing difficulties and an increased risk of overdose and death.8

The use of benzodiazepines to help with the comedown effects of stimulant drugs (such as amphetamines or ecstasy) may result in dependence on both types of drug.

Mixing different medications can also have negative effects. If you have concerns about taking medications, or drinking alcohol with medication, you should consult a health professional.

Mixing alcohol

Alcohol interacts with many drugs including medications, over-the-counter medicines and illegal drugs.9

Mixing alcohol and medicines can be harmful.

Alcohol and some medications can make you tired, drowsy, or lightheaded. When mixing alcohol and medication the effects can be intensified.10

Other effects of mixing alcohol and medication include:

  • difficulty concentrating
  • inability to perform simple tasks
  • risk of falls and injuries (especially in older people).9

Mixing alcohol with illegal drugs can have various effects depending on the type of drug.

Alcohol can increase the risk of drowsiness when mixed with other depressant drugs such as GHB or heroin. This can lead to overdose.3

Mixing alcohol with cocaine produces a chemical called cocaethylene, which is toxic and is associated with seizures, liver damage, and compromised immune system.11

Overdose and polydrug use

In Australia, many fatal drug overdoses are caused by mixing drugs.

A recent report by the Australian Bureau of Statistics found that multiple drugs were found in over half (59%) of unintentional drug overdoses. It is rare for an overdose to be from a single drug.

Polydrug deaths involving four or more substances have increased significantly in recent years.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top