Methamphetamine — also known as ice or crystal meth — is a highly addictive psychostimulant drug similar to amphetamine. It has powerful euphoric effects similar to those of cocaine. But, its use can also be life-threatening.

Methamphetamine increases the levels of naturally occurring dopamine and norepinephrine in the brain.

The effect lasts longer than those of cocaine, and it is cheaper and easy to make with commonly available ingredients. Street names for this drug include chalk, crank, ice, crystal meth, and speed.

According to the National Institute on Drug Abuse (NIDA), around 2.6 million people aged 12 years and older used methamphetamine in the United States in 2019. NIDA also estimated that 1.5 million of them (approximately 57.7%) have a misuse disorder.

Fast facts on methamphetamine

  • Methamphetamine is neurotoxic and can damage dopamine and serotonin neurons in the brain.
  • Most methamphetamine is made illegally, and it may contain caffeine, talc, and other toxic substances.
  • Its use is linked to higher frequencies of unprotected sexual intercourse and violent behavior.
  • Studies suggest that it may lead to structural and functional changes in the brain associated with emotion and memory, and that some of these may be irreversible.
  • Toxicity increases when it is used with alcohol, cocaine, or opiates.
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This article explores the effects of methamphetamine, dosage, side effects, and health risks. It also describes withdrawal from the drug, dependency treatment, and the extent of its use in the United States.

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Methamphetamine is similar to amphetamine. It is a commonly used illegal drug.

Methamphetamine is a white, odorless, bitter-tasting crystalline powder that easily dissolves in water or alcohol.

Scientists developed methamphetamine from its parent drug, amphetamine, in the early 20th century. Pharmaceutical companies first marketed it as a nasal decongestant and respiratory stimulator.

Healthcare professionals may prescribe amphetamine to treat some medical conditions, including:

Methamphetamine is used illegally for its pleasurable effects. Misuse can be hazardous and even life threatening.

During World War II, armed forces used methamphetamine to keep personnel alert and improve endurance and mood.

In time, it became clear that methamphetamine was dangerously addictive. In the 1970s, regulators added the drug to the Schedule II list of controlled substances in the U.S. Methamphetamine is illegal except when a physician prescribes it for a very limited number of medical conditions.

Methamphetamine is potent and easy to produce, so it remains a serious drug of misuse. Long-term use is associated with devastating effects on the individual and society.

Illegal forms of methamphetamine can be smoked, snorted, injected, or ingested orally.

Smoking or injecting methamphetamine causes an immediate, intense “rush” or feeling of bliss that lasts for a few minutes.

Snorting produces a euphoric high, instead of an intense rush, within 3–5 minutes of ingestion. A person who takes methamphetamine orally can feel the effects within 15–20 minutes.

The effects of methamphetamine can last for many hours, and it can take up to 4 days to leave a person’s body.

Learn more about how long meth stays in a person’s system.


People take methamphetamine for its pleasurable effects.

These include:

  • increased wakefulness
  • higher levels of physical activity
  • decreased appetite
  • a sense of well-being or euphoria

A person may also experience:

How it works

The pleasurable effects of methamphetamine happen when the body releases very high levels of the neurotransmitter dopamine. This is the brain chemical involved in motivation, pleasure, and motor function.

As with many stimulants, people often misuse methamphetamine in a “binge and crash” pattern. People often try to maintain the high by taking more of the drug before the first dose wears off.

The drug acts on parts of the brain involved in reward, which makes taking another dose tempting.

Some people use methamphetamine continuously for several days, avoiding food and sleep while taking the drug.

However, scientists think these high dopamine levels help make the drug more toxic to nerve terminals in the brain.

Methamphetamine is different from and more dangerous than other stimulants because a larger percentage of the drug remains unchanged in the body. This allows the drug to be present in the brain longer, extending the stimulant effects.

When healthcare professionals prescribe methamphetamine legally, they typically prescribe dosages of 5 milligrams (mg), 10 mg, or 15 mg daily.

Since illegal drugs are not regulated, there is no way to know how much methamphetamine is in each dose.

An overdose can lead to a high body temperature, heart attack, and seizure. If not treated immediately, an overdose can result in organ failure and death.

People use methamphetamine because they enjoy the effects. However, it can have some dangerous side effects.

These include:

The following symptoms of methamphetamine psychosis are also possible as long-term side effects:

Paranoia can result in thoughts of suicide.

Psychotic symptoms can last for months or years after discontinuing methamphetamine use. And they can spontaneously reoccur.

Methamphetamine misuse can cause significant brain changes. Various studies have demonstrated alterations in the brain’s dopamine system activity associated with reduced motor speed and impaired verbal learning.

Additional research has revealed structural and functional changes in the parts of the brain that control emotions and memory.

Methamphetamine use can lead to several health problems, including dependence, heart problems, and other physical and mental health issues.

Addiction and dependence

The drug has a high potential for misuse and dependence. Tolerance develops quickly, and psychological addiction can develop within a relatively short space of time.

Methamphetamine is highly addictive. This is because dopamine remains in the brain’s synapses for long periods after use. The dopamine keeps the brain cells activated, allowing the user to experience powerful feelings of euphoria.

After a while, a person cannot produce dopamine naturally and requires the drug to feel normal, needing larger doses to experience feelings of pleasure.

Stopping methamphetamine use suddenly does not cause a physical withdrawal, as with heroin. Instead, the person may feel extreme fatigue, mental depression, irritability, apathy, and disorientation.

Learn more about drug dependence.

Heart problems and stroke

Behind overdose and accidents, cardiovascular disease is a leading cause of death among those who use methamphetamine.

Misuse of the drug is associated with high blood pressure, which may lead to stroke. Other cardiac issues associated with methamphetamine include:

Tooth decay

Methamphetamine misuse can also cause severe tooth decay in which teeth either rot, known as “meth mouth,” or need extracting.

A person who misuses methamphetamine may have less saliva in the mouth. This promotes bacterial growth, tooth decay, and oral tissue damage.

Experts think other causes include:

Learn more about meth and face sores.

Parkinson’s disease

Methamphetamine may have neurological effects that do not go away after a person stops using the drug.

A 2018 study linked methamphetamine misuse to a moderately increased risk of Parkinson’s disease and premature onset. However, the authors suggest that more research is needed to assess how other factors affect an individual’s risk of developing Parkinson’s.

Toxicity risks for producers

Illegal drug manufacturers are called “cooks.” They are at risk of numerous injuries related to the production of methamphetamine.

Anyone in the area of a methamphetamine laboratory is also at risk of exposure to chemicals.

A 2015 CDC report recorded injuries from 1,325 meth-related chemical incidents in five U.S. states from 2001–2012. The report revealed that 162 people were injured, including at least 26 children.

Other risks

Other health risks include a higher chance of contracting a bloodborne disease, such as hepatitis or HIV, among those who inject the drug.

Social consequences of long-term use include financial pressures, problems with work, and challenges with family relationships.

Withdrawal syndrome occurs when someone stops taking methamphetamine following chronic use.

Symptoms include:

According to NIDA, the most effective treatment strategies for people with methamphetamine addiction include:

There are currently no available medications that counteract the effects of methamphetamine or help to prolong abstinence. However, NIDA is funding research into developing medications to treat stimulant addiction.

A person wanting to stop methamphetamine use should speak with a healthcare professional, who can provide support and referrals to treatment centers.

People or caregivers can find further support for methamphetamine addiction using the Substance Abuse and Mental Health Services Administration (SAMHSA) website.

According to NIDA, in 2020, around 2.6 million people aged 12 years and older had used methamphetamine in the past 12 months.

Transnational criminal organizations in Mexico produce most methamphetamine. However, it can also be made in small home laboratories using inexpensive over-the-counter ingredients, such as pseudoephedrine.

Producers often mix it with other substances, including fentanyl.

By law, pharmacies and retail stores must keep pseudoephedrine and ephedrine products behind the counter. They also need to keep a log to track who buys it and in what amounts.

Commercially, methamphetamine is only available under the brand name Desoxyn in 5-mg tablets. It has very limited use in treating obesity and attention deficit hyperactivity disorder (ADHD). Healthcare professionals also prescribe it off-label to treat narcolepsy.

Methamphetamine is a highly addictive stimulant drug that is derived from amphetamine. It can be smoked, injected, snorted, or ingested orally.

People take it for its pleasurable effects, including feelings of euphoria and increased wakefulness. However, people who misuse methamphetamine can experience severe side effects, such as addiction, anxiety, and psychosis.

Potential long-term side effects of misuse can include heart problems and stroke, reduced cognitive function, and complete tooth decay.

People experiencing methamphetamine addiction should speak with a healthcare professional who can provide support and treatment pathways. Effective treatment options include behavioral therapies and motivational incentives.