Last published: October 07, 2020

What are stimulants?

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

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

How are they used?

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

Explore stimulants on the Drug Wheel

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Other commonly used stimulants

  • Methylphenidate (prescribed)
  • Pseudoephedrine

Effects of stimulants

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.

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).

Generally speaking, in small to low doses the following effects may be experienced:

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

Higher doses may result in:

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

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, and could cause:

  • Amphetamines + some antidepressants: elevated blood pressure, which can lead to irregular heartbeat, heart failure and stroke.4
  • 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

Health and safety

Use of stimulants is likely to be more dangerous when:

  • taken in combination with alcohol or other drugs, particularly other stimulants such as crystal methamphetamine (‘ice’) or ecstasy
  • driving or operating heavy machinery
  • judgement or motor coordination is required
  • 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 they 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 them.

People who are psychologically dependent on stimulants may find they 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.

Help and support

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  1. Brands, B., Sproule, B., & Marshman, J. (Eds.). (1998). Drugs & drug abuse (3rd ed.). Ontario: Addiction Research Foundation.
  2. Campbell, A. (2000). The Australian illicit drug guide. Melbourne: Black Inc.
  3. Upfal, J. (2006). The Australian drug guide (7th ed.). Melbourne: Black Inc.
  4. Independent Scientific Committee on Drugs. (2013). Amphetamine/’Speed’.
  5. Cracks in the Ice. (2017). Using ice with other drugs.