Last published: June 06, 2024

What are stimulants?

Stimulants are a class of drugs that speed up messages travelling between the brain and body. They can make a person feel more awake, alert, confident or energetic.1

Stimulants include caffeine, nicotine, amphetamines and cocaine. Large doses can cause over-stimulation, resulting in anxiety, panic, seizures, headaches, stomach cramps, aggression and paranoia. Long-term use of strong stimulants can have adverse effects.

What do stimulants look like?

Stimulants can be in the form of tablets, capsules, powders, and small chunky clear crystals or a white or brownish crystal-like powder with a strong smell and bitter taste.

Other names

Uppers, beans, pep pills, speed, dexies, smart pills

How are they used?

Illicit stimulants are usually snorted, swallowed, smoked or injected. Prescribed stimulants are usually taken orally, and how long the effects last differs depending on the type.1,2

Explore stimulants on the Drug Wheel

Drug wheel segment - Stimulants segment@2x.png

Other commonly used stimulants

  • Methylphenidate (prescribed)
  • Pseudoephedrine

Effects of stimulants

Use of any drug can have risks. It’s important to be careful when taking any type of drug.

Stimulants 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 with illegally produced drugs).

For lower doses, effects include:

  • euphoria
  • heightened feelings of wellbeing
  • increased heart rate and blood pressure
  • increased alertness
  • talkativeness
  • reduced appetite.1, 2

Higher doses may result in: 

  • anxiety
  • tension
  • increased body temperature
  • nausea
  • tremor
  • seizures
  • coma
  • death. 1, 2

Using stimulants with other drugs

The effects of taking stimulants with other drugs − including over-the-counter or prescribed medications − can be unpredictable and dangerous.

  • Amphetamines + some antidepressants: elevated blood pressure, which can lead to irregular heartbeat, heart failure and stroke.3
  • Amphetamines + alcohol, cannabis or benzodiazepines: the body is placed under a high degree of stress dealing with the conflicting effects of each drug, which can lead to an overdose.4
  • Ice + speed or ecstasy: enormous strain on the heart and other parts of the body, which can lead to stroke.5
  • Ice + alcohol, cannabis or benzodiazepines: enormous strain on the body, and more likely to overdose. The stimulant effects of ice may mask the effects of depressant drugs like benzodiazepines and can increase the risk of overdose.5

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. Polydrug use can involve both illicit drugs and legal substances, such as alcohol and medications.


Reducing harm

Use of stimulants is likely to be more dangerous when:

  • combined with alcohol or other drugs
  • driving or operating heavy machinery
  • judgement or motor coordination is required
  • the person is alone (in case medical assistance is required)
  • the person has a mental health problem
  • the person has an existing heart problem.

Dependence and tolerance

People who use stimulants regularly can develop dependence and tolerance to them. Tolerance means you need to take larger amounts of stimulants to get the same effect.

Dependence on stimulants can be psychological, physical, or both. People who are dependent on stimulants find that using the drug becomes far more important than other activities in their life. They crave them and find it very difficult to stop using.

People who are psychologically dependent on stimulants may feel an urge to use them when they are in specific surroundings or socialising with friends.

Physical dependence occurs when a person’s body adapts to the stimulants and gets used to functioning with the stimulant present.

Getting help

If your use of stimulants 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 the National Alcohol and Other Drug Hotline on 1800 250 015 for free and confidential advice, information and counselling about alcohol and other drugs

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  1. Brands B, Sproule B, Marshman J. Drugs & Drug Abuse. 3rd ed. Ontario: Addiction Research Foundation; 1998.
  2. Farzam K  Faizy R Saadabadi A. Stimulants 2022 [cited: 02.05.2022].
  3. Vo K Neafsey P Lin C. Concurrent use of amphetamine stimulants and antidepressants by undergraduate students. Patient Preference and Adherence 2015;9.
  4. Australian Government Department of Health. Poly Drug Use What You Need To Know About Mixing Drugs 2014.
  5. Cracks in the Ice. What happens when you use crystal methamphetamine with other drugs? 2020 [cited: 02.05.2022].