How Long Does Meth Stay in Your System?

Methamphetamine, commonly called meth, is an intense synthetic central nervous system stimulant that creates a fast, euphoric high which soon diminishes, causing a crash that motivates the user to seek more.

The intense addictive quality of this drug and its devastating effects on the body and mind have led it to be classified as a Schedule II substance in the US, making its recreational use highly illegal.

Methamphetamine is typically either smoked in a small glass pipe or injected. Both of these methods cause the drug to reach the brain very quickly, with injection being the fastest. A large amount of the drug reaching the brain at once causes euphoria – an intensely pleasurable sensation, followed by hours of energy in which an intoxicated individual will often be very active and sometimes productive.

As a fast-acting stimulant, meth does not stay in the system for very long. The effects of meth last for around 8-24 hours, depending on how much is taken, how well the kidneys and liver function, and the individual user’s body chemistry. It has a plasma half-life of 12-34 hours. This means that it takes 12-34 hours for the amount of meth in a person’s blood to be reduced by half.

Meth Withdrawal

meth withdrawalsBy this point, withdrawal symptoms will begin to occur, especially if the individual is a heavy, long-term user. Withdrawal symptoms from this drug are extremely unpleasant and come with intense cravings. This often motivates a user to take more and then more of the drug. The longer and heavier use is, the longer it takes to leave the system entirely. Typically, it takes 2-10 days for meth to be flushed out of the system entirely.

Methamphetamine withdrawal symptoms include:

  • Increased appetite
  • Anxiety and depression
  • Inability to feel pleasure (anhedonia)
  • Anger and aggression
  • Irritability
  • Fatigue
  • Lethargy
  • Muscle weakness
  • Sweating
  • Headaches
  • Fever
  • Dizziness
  • Inability to concentrate
  • Paranoia
  • Delusions
  • Psychosis
  • Suicidal ideation

Though not directly life-threatening like the symptoms of alcohol and benzodiazepine withdrawal, the psychological effects can lead people in withdrawal from meth to attack others or harm themselves.

It’s highly recommended that “cold turkey” detoxification is not attempted without medical supervision.

Methamphetamine and Drug Tests

Urine tests can usually detect meth for up to 72 hours after the last dose. However, in heavy, chronic users, it can be detected in urine for up to a week. Much of the methamphetamine ingested by users is quickly processed by the liver and kidneys and passes out of the body unchanged – up to 54 percent, according to the National Highway Traffic Safety Administration.

Other ways that meth use can be detected is through hair and saliva tests. A saliva swab can detect methamphetamine for 1-4 days after the last dose was taken. However, synthetic substances like meth can stay in a person’s hair for much longer. It can be detected by a hair test for up to 90 days after last use, depending on what type of hair test is used.

Methamphetamine is an incredibly harmful drug, and any suspected addiction to it should be treated as soon as possible. Recovering from meth addiction can be difficult, but the sooner a person seeks treatment, the easier it will be.

Last updated on November 26, 20182018-11-26T17:08:57
About the reviewer
Meredith Watkins is a licensed Marriage and Family Therapist who specializes in dual diagnosis and eating disorders.
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