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:

• increased energy and talkativeness
• increased attention and alertness 
• a sense of euphoria and wellbeing 
• increased heart rate, body temperature, and sweating
• increased sex drive
• decreased appetite 
• jaw clenching and teeth grinding 
• nausea and vomiting 
• dilated pupils 
• dry mouth 
• nervousness, anxiety, and paranoia.

In the days following methamphetamine use, other effects may include:

• restless sleep and exhaustion
• headaches
• dizziness and blurred vision
• paranoia, hallucinations, and confusion
• irritability, mood swings, and depression. 

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