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Methamphetamine is a powerful stimulant that's similar to amphetamine. It is sometimes prescribed to treat ADHD or obesity. The illegal form of this drug is usually called meth. It may also be called crystal meth, speed, ice, crystal, glass, or chalk. It's often made in home labs from cheap, sometimes toxic ingredients.

Meth is usually sold as a white powder or small, clear crystals that may look like ice or rocks. It can be smoked, snorted, or swallowed. It can also be dissolved in water or alcohol and injected.

Meth is very addictive, and it can lead to stimulant use disorder. If a person stops using meth, they may have withdrawal symptoms such as depression, anxiety, and paranoia.

Effects of meth

  • When meth is smoked or injected, the person feels an intense pleasurable rush that lasts only a few minutes. Smoking it leaves a residue that can be smoked again. This lets the person feel the effects of the drug for up to 12 hours or more.
  • When meth is snorted or taken by mouth, the person feels happy (euphoric) for a short time but doesn't get the intense rush caused by smoking or injecting the drug.

People who use meth tend to use it again and again (binge) and then crash afterward.

People who use meth may become anxious, confused, and violent. It can affect a person's brain so that they can't tell what is real (psychosis). For example, they may:

  • Fear that others want to harm them (paranoia).
  • See or hear things that seem real but aren't (hallucinations).
  • Believe things that aren't true (delusions).

In small doses, methamphetamine can make a person feel very awake and active and decrease their appetite. In high doses, it can raise body temperature. This can be dangerous or even deadly. It can also cause seizures. Meth increases heart rate and blood pressure, so it can cause permanent damage to blood vessels in the brain. This can lead to a stroke.

Meth can be detected in a urine drug screen up to 48 hours after use.

Signs of use

Signs that a person may be using meth include:

  • Going long periods of time without eating or sleeping.
  • Losing weight.
  • Acting nervous. The person may talk fast, seem irritated, or move around a lot.
  • Having wide (dilated) pupils in the eyes and an increased pulse rate.
  • Having dental problems.
  • Having personality changes.


Current as of: March 21, 2023

Author: Healthwise Staff
Clinical Review Board
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