How Does Ice Work

Ice and the brain

Ice triggers the release of two chemicals in the brain, dopamine and noradrenaline. These chemicals make us feel alert and excited. This can cause both short term and long term problems.

The effects of ice

Depending on how much is taken, the effects of ice often last for between 4 and 12 hours.

The effects of ice are usually felt quickly, but can take 1 to 2 days to completely leave the body.

The physical effects of ice can include:

SHORT TERM

Headaches and feeling dizzy
Enlarged pupils and blurred vision (problems seeing)
Dry mouth
Jaw clenching, teeth grinding
Insomnia (Not being able to sleep)
Increased alertness and talking a lot
Euphoria or feeling good

Trembling and shaking
Sweaty, cold and clammy skin
Faster breathing and warmer body temperature
Increased heart rate and blood pressure
Reduced appetite
Stomach cramps (pain)
Dehydration (loss of water)
Aggressive behaviour
Increased energy

LONG TERM

Stroke
Dental problems: painful or damaged teeth, gum disease
Dependence (addiction)
Poor concentration and memory

Increased risk of hepatitis C and (when injecting)
Heart and lung problems, chest pains
Kidney problems, including kidney failure
Weight loss
Exhaustion (being very tired)
Movement problems

The comedown phase and withdrawal

A 'comedown' is often experienced when the drug wears off. Symptoms can last for a few days and can include feeling down or depressed, exhausted and anxious.

Withdrawals are unpleasant symptoms experienced by people who are (addicted) on ice and who stop taking the drug. Symptoms can last up to several weeks and can include headaches, sleeping lots, cramps and vomiting, as well as restlessness and aggression.

To learn more about what happens when a person stops taking ice click here.

Key Sources
Australian Drug Foundation. (2016). Amphetamines. Melbourne: State Government Victoria.

Australian Institute of Health and Welfare. (2018). Alcohol, tobacco & other drugs in Australia. Canberra: Australian Institute of Health and Welfare.

Darke S., Kaye S., McKetin R., Duflou J. (2008). The major physical and psychological harms of methamphetamine use. Drug Alcohol Rev 2008; 27: 253–62.

Darke, S., Kaye, S., and Duflou, J. (2017). Rates, characteristics and circumstances of methamphetamine-related death in Australia: a national 7-year study. Addiction.

McKetin, R., & Black, E. (2014). Methamphetamine: What you need to know about speed, ice, crystal, base and meth. Sydney: National Drug and Alcohol Research Centre, University of New South Wales.

See ‘The effects of ice on the brain’ fact sheet for sources related to cognitive effects.