What to Know About Methamphetamine Use

Methamphetamine also known as crystal meth
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Whether it's injected, snorted, or smoked, methamphetamine is a highly addictive drug that affects the brain and central nervous system. Methamphetamine increases levels of the neurotransmitters dopamine, norepinephrine, and serotonin which stimulates brain cells, enhancing mood altering levels of energy, alertness and other bodily functions.

In the United States, the Drug Enforcement Administration (DEA) classifies methamphetamine as a Schedule II substance. This means that the drug is illegal when used recreationally and that it has a high potential for misuse, but that there are some restricted medical uses.

Also Known As: Some common street names for methamphetamine include meth, crystal, speed, crank, and tweak.

Drug Class: Meth is a stimulant drug that increases activity in the central nervous system.

Common Side Effects: Meth use can lead to side effects such as nausea, diarrhea, vomiting, seizures, anxiety, and depression. 

How to Recognize Methamphetamine

Methamphetamine most often takes the form of a white, crystalline powder. While it is odorless, it has a bitter taste. The powder dissolves easily in water. Crystal meth looks like chips of clear ice. Illegal forms of the drug can be snorted, smoked, injected, or orally ingested.

What Does Methamphetamine Do?

When methamphetamine is injected or smoked, it immediately produces an intensely pleasurable sensation known as a "rush" or a "flash." It does so by releasing high levels of dopamine in the brain. Snorting methamphetamine produces a euphoric sensation, but not a rush.

The effects of methamphetamine are similar to those of other stimulants and include:

  • Agitation
  • Decreased appetite
  • Feelings of pleasure
  • Increased sociability
  • Low inhibitions
  • Mental confusion
  • Physical alertness

Even when taken in small amounts, methamphetamine can cause increased wakefulness and physical activity. A decreased appetite is also common.

What the Experts Say

Research published in 2014 found that methamphetamine has neurotoxic effects, leading to damage to the serotonin and dopamine receptors in the brain. 

The long-term use of methamphetamine can cause damage to the brain similar to other conditions that injure the brain. This brain damage lingers for months even after use has stopped.

The neurological effects of meth use can be permanent, even after a person quits. Researchers have found that methamphetamine use can lead to a higher risk of Parkinson's disease.

Methamphetamine misuse can also produce extreme anorexia. Even over a short period of use, methamphetamine can cause drastic changes in physical appearance.

Off-Label and Approved Uses

In the United States, dextromethamphetamine hydrochloride is an FDA-approved treatment for obesity and ADHD in adults and children. While approved, the FDA cautions that there is a high potential for dependence and its therapeutic benefits tend to be quite limited.

Methamphetamine is occasionally used off-label in the treatment of sleep disorders such as idiopathic hypersomnia and narcolepsy.

Meth Side Effects

Physically, meth can increase respiration, heart rate, and blood pressure. It can cause hyperthermia and an irregular heartbeat. There is also the potential for cardiovascular collapse.

Other effects of meth use on the central nervous system can produce symptoms like irritability, confusion, anxiety, paranoia, and aggressiveness. Some people also suffer from prolonged insomnia and tremors.

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

Signs of Use

Some of the common signs that someone might be using methamphetamine include:

  • Presence of drug paraphernalia
  • Hyperactivity
  • Dilated pupils
  • Poor appetite
  • Sudden weight loss
  • Burns on lips and fingers
  • Jerky movements and twitching
  • Skin sores and scabs
  • Changes in sleep patterns
  • Rotten teeth

Overdose is another danger associated with methamphetamine use. An overdose results in a rapid onset of physiological deterioration, eventually leading to a heart attack or stroke. Because of the speed of 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 will have a high temperature, kidney failure, and cardiovascular collapse. The truly scary part is that it will all happen very quickly.

If you suspect that someone has overdosed on methamphetamine, contact emergency services immediately.

Common Questions

As a result of anti-drug campaigns and popular media, many people have a mental picture of what they think a "meth user" looks like. Often it's an image of someone with rotten teeth who is dirty, gaunt, and scabbed.

Pictures of people who have misused meth and have undergone shocking physical changes are graphic and can make for a convincing argument against drug use, but they paint a very narrow picture of who uses meth.

In reality, approximately 1.6 million people (0.6% of the U.S. population) reported using methamphetamine in the past year, according to the 2017 National Survey on Drug Use and Health (NSDUH). Methamphetamine addiction can affect anyone.

Tolerance, Dependence, and Withdrawal

Methamphetamine has a high risk of tolerance and dependence. Tolerance occurs when a person needs to take increasing amounts of the drug in order to achieve the same "high" they initially experienced. Tolerance to methamphetamine develops quickly. 

How Long Does Methamphetamine Stay in Your System?

How long meth stays in your system depends upon a variety of factors including metabolism, body mass, and the frequency of use. It can usually be detected by blood test for one to three days, by urine test for up to a week, and by hair follicle test for up to 90 days.


Methamphetamine is highly addictive and people can 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.

People who use meth will seek and use more methamphetamine in order to get back to that state of pleasure or to just feel "normal" again. This cycle results in physical dependence on the drug and often requires serious treatment to successfully break.


Once you have decided to quit, detoxification is the first step. This process begins once you stop taking methamphetamine and continues until your system is free of it and has adjusted to being off the drug. Initial withdrawal symptoms usually begin within 24 hours of the last dose, peak after about 10 days, and may last three weeks or more.

People often go through the detox and withdrawal process at home, but residential and outpatient treatment options are also available. If you decide to go through the process at home, make sure to inform your doctor and have a friend or loved one check in on you often.

The withdrawal from a drug like meth is not easy and is filled with days or weeks of many symptoms. People who stop using methamphetamine experience irritability, depression, fearfulness, and loss of energy.

Possibly the hardest withdrawal symptom to overcome, however, is the extreme craving for the drug.

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.

How to Get Help

If you or a loved one is ready to quit using methamphetamine, there are resources available that can help. You can start by talking to your doctor who can then assess your current physical health, talk to you about the next steps, and refer you to treatment centers in your area.

Long-term treatments typically utilize behavioral therapy approaches including contingency management (CM) and cognitive-behavioral therapy (CBT).

  • Contingency management allows people to earn vouchers for desired rewards in exchange for staying drug-free.
  • Cognitive-behavioral therapy works to change harmful thought patterns and behaviors that contribute to drug use. This approach also teaches people new coping skills and strategies that can help them abstain from drug use in the future.

There are a few medications that may be useful in the treatment of some patients with methamphetamine use such as naltrexone, modafinil, or bupropion. There is research ongoing around the potential use of anti-methamphetamine monoclonal antibodies.

Other approaches that may be used include individual counseling, drug testing, support groups, and 12-step programs.

If you or a loved one are struggling with substance use or addiction, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

For more mental health resources, see our National Helpline Database.

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Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Buddy T
Buddy T is an anonymous writer and founding member of the Online Al-Anon Outreach Committee with decades of experience writing about alcoholism.