Methamphetamine

Methamphetamine is a powerful synthetic stimulant. It is illegal, highly addictive and very dangerous to your health. 

On this page:

• About methamphetamine
• Short-term effects of methamphetamine
• Long-term effects of methamphetamine
• Risks related to methamphetamine use
• Substance use disorders and withdrawal

About methamphetamine

Methamphetamine is a synthetic stimulant made from chemical ingredients. It is also known as:

• ice
• meth
• chalk
• crank
• crystal meth

Methamphetamine is a strong stimulant, but it also produces compulsive effects and dependence. It comes in several forms:

• powder
• crystals
• tablets

It can be smoked, snorted, injected or swallowed.

Any methamphetamine used in Canada is produced illegally.  

Methamphetamine is controlled under Schedule I of the Controlled Drugs and Substances Act (CDSA). Activities such as sale, possession or production are illegal, unless authorized for medical, scientific or industrial purposes. Pharmaceutical methamphetamine is not authorized in Canada.

Short-term effects of methamphetamine

How quickly methamphetamine affects you depends on how you take it. You will feel its effects within:

• seconds, if you inject or smoke it
• 3 to 5 minutes, if you snort it
• 20 to 30 minutes, if you swallow it as tablets

Methamphetamine can have dangerous and unpredictable, short-term mental and physical effects. These usually last 8 hours but can sometimes last up to 24 hours.

Mental effects

Methamphetamine users may experience a temporary rush of well-being (euphoria). They may also feel:

• higher energy and less fatigue
• increased wakefulness and alertness
• a rapid flow of ideas and speech
• a sense of great confidence, elevated mood
• increased libido (sexual drive)
• decreased appetite

At high doses, methamphetamine may cause unpleasant effects, such as restlessness and anxiety. Sometimes mental performance can be impaired.

Physical effects

Methamphetamine users may also experience physical effects, such as:

• stomach ache
• fast and irregular heartbeat
• increased blood pressure, leading to headache and dizziness
• increased breathing
• increased body heat
• dilated pupils
• twitching muscles

Smoked methamphetamine may cause difficult breathing and shortness of breath.

Contaminated equipment can spread infectious diseases such as:

• HIV
• hepatitis B
• hepatitis C

Binge effects

If you binge on methamphetamine, the euphoria decreases over time and unpleasant effects and compulsive behaviour increase.

Binge users may display highly focused and/or repetitive behaviours. They may also experience:

• sleeplessness
• paranoia
• hallucinations

As a result, they may be irritable and prone to unprovoked aggression. Cravings for the drug may become extremely intense.

After binges, methamphetamine users “crash.” They may sleep for long periods of time and feel hungry, depressed or anxious, as well as continuing to crave methamphetamine.

Long-term effects of methamphetamine

Long-term effects are complications that result from repeated and sustained short-term effects. Methamphetamine users go through periods of stimulation and depression

Mental effects

Repeated methamphetamine use changes your moods and mental states.

Over time, problematic use may cause any or all of these symptoms:

• brain damage, some permanent
  • inability of the brain to produce chemicals
  • inability to control urges
  • difficulty staying attentive
  • short- or long-term memory problems
  • loss of hand and finger dexterity

• behaviour
  • high-risk sexual activities
  • long-lasting or permanent aggression

• psychosis and/or paranoia
  • erratic or bizarre thought patterns
  • losing touch with reality
  • hallucinations

• suicidal feelings, especially during withdrawal

It is unclear if psychosis and depression contribute to, or result from, methamphetamine use.

The mental effects of methamphetamine combined with psychiatric symptoms harm a person’s ability to manage their lives properly.  

Physical effects

The most dangerous long-term physical effects are cardiovascular. Even young users can suffer from:

• heart attack
• stroke
• sudden cardiac death
• reduced heart function and shortness of breath

Methamphetamine dependence may cause further harms, such as:

• severe, poor nutrition
• weakened immune system
• severely damaged skin
  • sores can turn into severe life-threatening infections
  • sensation of insects crawling under the skin, leading to excessive scratching
• methamphetamine (meth) mouth or extended dry mouth
  • permanent bad taste in the mouth
  • cavities and/or lost teeth

Using methamphetamine during pregnancy may be harmful to your unborn child. It is associated with:

• premature delivery
• a decrease in the mother’s appetite
• slow fetal growth, leading to low birth weight

Risks related to methamphetamine use

Methamphetamine overdoses most commonly produce exaggerated mental and physical effects such as:

• agitation
• fast and irregular heartbeat
• high blood pressure
• rapid respiration or difficulty breathing
• psychosis
• excessive body heat or shivering
• liver and/or kidney failure

Reports of overdose also note convulsions and coma.

Methamphetamine deaths result mostly from heart or lung complications. Deaths from choking on vomit or from infections are also frequent.

High doses of methamphetamine have also been linked to fatal accidents, suicides and violent aggression causing death.

The risk of accidental overdose is also higher with co-use of other substances (for example, alcohol, opioids).

Substance use disorders and withdrawal

Methamphetamine is highly addictive. Tolerance develops the more you use. This means that you need more and more methamphetamine to get the desired effects. Difficulty getting “high” causes great frustration and unstable behaviour.

Unlike with other substances of problematic use, methamphetamine withdrawal produces mostly psychological symptoms. If you stop using methamphetamine abruptly you experience intense cravings. These cravings are so intense that you cannot focus on anything else. Eventually, your life may be taken over by the urge to get and use the drug.

Other symptoms of withdrawal include:

• intense fatigue
• difficulty sleeping or disturbed sleep
• feeling hungry all the time
• dissatisfaction, inability to feel pleasure
• depression, anxiety and irritability

Coming down from a methamphetamine-induced state is commonly known as "tweaking." When the effects are wearing off, you feel a powerful combination of:

• drug craving
• anxiety
• sleeplessness
• irritability and aggression

As the effects of methamphetamine continue to wear off, you can also experience:

• poor concentration
• possible paranoia and hallucinations

This is a dangerous state, both for you and those around you. You are fueled by intense, negative psychological effects. You may be in a psychotic state or disconnected from reality. You can also become hostile and violent or you may self-mutilate, attempt suicide or attack others for no reason.

Unstable behaviour may not be apparent if other substances are used during withdrawal.