Methamphetamine use stimulates the brain and central nervous system, and can result in a variety of adverse outcomes. The effect that methamphetamine has on an individual depends on a number of factors. These include:

• how much methamphetamine is taken
• the method of use
• the form and purity of the methamphetamine
• the height and weight of the user
• the user’s current physical and mental health status
• the user’s previous experience with methamphetamine (i.e. new user vs frequent user)
• whether other substances (alcohol, tobacco, medications, or other illicit drugs) are used at the same time as methamphetamine.

Immediate effects of methamphetamine use can include feelings of euphoria, confidence and energy. People who use methamphetamine may feel excited, talkative, or hyperactive, and may have an increased sex drive, reduced appetite and decreased need for sleep. 

Methamphetamine use can also result in an increased heart rate and blood pressure, and feelings of irritability, restlessness, paranoia and anxiety. In some cases, it can also lead to aggressive or violent behaviour, heart attack, stroke, kidney damage, and fatal or non-fatal overdose. 

When people stop using methamphetamine, they may also experience withdrawal symptoms (even if they don’t have a substance use disorder). These include:

•           Depression
•           Agitation and irritability
•          Paranoia and anxiety
•          Sleep problems
•           Poor concentration
•           Intense cravings.

These symptoms are worse in the first couple of days after stopping methamphetamine use, but can last for a few weeks to a few months.

For more information about the longer-term effects of methamphetamine, see FAQs What are the physical health risks of methamphetamine use? and What are the mental health risks of methamphetamine use?