The Effects of Methamphetamine

Short-Term and Long-Term Effects

Man Shooting Meth
Meth Has Many Negative Effects. © PhotoXpress

Methamphetamine is a highly addictive drug, whether injected, snorted or smoked, that affects the brain and central nervous system. Methamphetamine increase levels of the neurotransmitter dopamine, which stimulates brain cells, enhancing mood and body movement.

Short-Term Effects

When methamphetamine is injected or smoked it immediately produces an intensely pleasurable sensation known as a "rush" or a "flash" by releasing high levels of dopamine in the brain.

Snorting methamphetamine produces a euphoric sensation, but not a rush.

Even taken in small amounts, methamphetamine can cause:

  • Increased wakefulness
  • Increased physical activity
  • Decreased appetite
  • Increased respiration
  • Hyperthermia
  • Increased heart rate and blood pressure
  • Irregular heart beat
  • Cardiovascular collapse

Other effects of meth use on the central nervous system can produce the following symptoms:

  • Irritability
  • Prolonged insomnia
  • Confusion
  • Anxiety
  • Tremors
  • Convulsions
  • Paranoia
  • Aggressiveness

Hyperthermia and convulsions can be fatal. Methamphetamine can also cause irreversible damage to the blood vessels in the brain, resulting in a stroke.

Long-Term Effects

Chronic meth use can result in:

  • Violent behavior
  • Psychotic behavior
  • Auditory hallucinations
  • Mood disturbances
  • Delusions and paranoia
  • Homicidal or suicidal thoughts

The long-term use of methamphetamine can cause damage to the brain similar to that caused by Alzheimer's disease, stroke, and epilepsy.

This brain damage lingers for months even after the user stops methamphetamine use.

Methamphetamine abuse can produce extreme anorexia. Even over a short period of use, methamphetamine can cause drastic changes in the appearance of the user. See The Face of Meth Use.


Unlike other drugs, a methamphetamine overdose gives no immediate signs to users.

Users can take a lethal dose and not immediately realize that they have just done so.

An overdose results in a rapid onset of physiological deterioration, eventually leading to a heart attack or stroke. Because of the rapid onset, death occurs suddenly and unexpectedly.

A meth overdose produces profuse sweating, rapid breathing, increased heart rate and dilated pupils. A person who has overdosed on meth with have a high temperature, kidney failure, and cardiovascular collapse -- and it will all happen very quickly.


Methamphetamine is highly addictive and users become physically dependent upon the drug quickly. Meth, like amphetamine, produces a rapid pleasurable feeling, which is followed by feelings of depression and irritability when the drug wears off.

Users will seek and use more methamphetamine in order to get back to that state of pleasure, or to just feel "normal" again, which results in a physical dependence on the drug. It is a never-ending cycle.

Do you think you may need treatment for drug abuse?

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People who stop using methamphetamine experience a wide variety of symptoms, including:

  • Irritability
  • Depression
  • Fearfulness
  • Loss of energy
  • Extreme craving for the drug

Meth withdrawal also results in actual physical symptoms:

  • Shaking or tremors
  • Nausea
  • Palpitations
  • Sweating
  • Hyperventilation
  • Increased appetite

People withdrawing from methamphetamine can alternate from wanting to sleep all the time, to not being able to sleep. Withdrawal symptoms can last for several weeks.

A.D.A.M. Illustrated Health Encyclopedia
AIRO, Montana State University at Bozeman
National Institute on Drug Abuse

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