How Long Does Meth Stay In Your System ?

Meth abuse in the United States is currently a widespread epidemic. Often this is the case because it is a drug that can be produced in the United States and does not have to be imported. This makes the drug cheaper and easier to access. Methamphetamine also has a longer “high” than most other recreational stimulants. (1) The effects on the body from methamphetamine use are great. This article will discuss how methamphetamine testing is done and how it affects the body.

How long is Meth in your system?

  • Methamphetamine has a longer half-life than other stimulant drugs such as cocaine. This causes the effect to last longer.
  • Due to it being processed in the United States the price of the drug is lower than that of cocaine whose base drug is processed in countries south of the United States.
  • The feelings of stimulation felt when taking methamphetamines is due to its effects on the sympathetic nervous system. (1)
  • When used only once methamphetamine can be found in the urine for up to 24 hours. But if use is constant or regular it can show up for up to 7 days after use. (3)
  • The normal amount of time for meth to show up in the urine can be anywhere between 2-4 days.
  • Toxicology results for meth can show false negatives because many legal medications can show similar results. These medications could be and are not limited to:
  1. Bupropion
  2. Labetalol
  3. Doxepin
  4. Ranitidine overdose
  5. Dexedrine
  6. Adderall
  • Testing can also show as negative due to being done too soon after ingestion. (7)

How long does Meth stay in your blood?

  • Blood tests are done when a drug containing methamphetamine is being used as a prescription. The test is done to prevent abuse. A concentration greater than 0.2mg/L can show an abuse of prescription medications.
  • Peak concentration show in the blood only a few hours after oral dosing.  The concentration of injection and smoking occur as fast as a few min. (9)

How long does Meth stay in your urine?

  • Usually, a positive result proves used over the past four days. If abuse is chronic it could prove used over the last week.
  • A urine test can show if the ingestion method was oral or injected. (9)

How long does Meth stay in your saliva and the hair?

  • Saliva nor hair follicle tests are not used for meth.

How is Meth metabolized in the body?

  • Meth crosses the blood brain barrier more rapidly than most drugs.
  • It is stronger than amphetamine and has an increased penetration on the CNS.
  • Its actions on the CNS are to bind to dopamine and norepinephrine. It also decreases the serotonin transporters. (1)

In this image you can see the blood brain barrier and how meth crosses and attaches itself toe the neurons.

How is meth metabolized in the body.
Picture 1: Blood brain barrier
Image Source:

Side effects of Meth use and abuse

  • Many of the effects on the body can be the acute or long term if the abuse is chronic.

Meth attacks the following body systems:


  1. Hypertension and tachycardia
  2. Arrhythmias
  3. Chest pain due to ischemic cardiac cells or infarction.
  4. With overdose, hypotension may be noted.

Central nervous system

  1. Seizures
  2. Jerking or choreoathetotic movements
  3. Inability to focus
  4. Headache
  5. Stroke
  6. Acute psychosis
  7. Agitation or violent activity
  8. Ultimately coma
  9. Impairment in episodic memory
  10. Executive function impairment- This causes abusers to not be able to learn from past errors.


  1. Barotrauma
  2. Wheezing


  1. Abdominal pain due to mesenteric vasoconstriction.
  2. Ulcers
  3. Ischemic colitis


  1. Renal failure
  2. Hypoxemia
  3. Rhabdomyolysis
  4. Necrotizing angiitis
  5. Acute interstitial nephritis


  1. Itchy skin
  2. Lesions due to trying to scratch delusions of parasites on the skin
  3. Abscess and cellulitis due to injecting.
  4. Chemical burns for those who are working in meth labs


  1. Severe caries
  2. Maxillary teeth breakdown.

In pregnancy and nursing will usually cause fetal death. (1,5,6)

One study showed that meth abusers showed a better chance of having Parkinson’s when compared to nonusers.

Meth Withdrawal symptoms

These symptoms can last up to two weeks after the last dosing. The length of time and severity of these symptoms depends on the amount of drug used.

  • Hypersomnia
  • Anhedonia
  • Irritability and violence
  • Aggression
  • Anxiety
  • Intense cravings
  • Hallucinations
  • Depression (3)

How can you help someone who is recovering from meth abuse?

First off you need to be able to spot the signs of abuse. Here are some of the short term and long term signs that someone is using meth.

Short term effects are as follows:

  • Higher than normal want to accomplish tasks. Finishing thing quicker than  normal.
  • Less need for sleep, or staying awake all night working.
  • Less need for eating or distaste for foods.
  • Not being able to sit still for any length of time.

Long term effects are as follows:

  • Hallucinations and or paranoid episodes
  • Feeling as if others are out to get them
  • The movement which appears to be repetitive.
  • Poor judgment and memory loss.
  • Drastic weight loss
  • Violence and aggression to loved ones or towards self.
  • Declining health and skin and mouth conditions.

How can you help once they are diagnosed and ready to stop?

  • There is no medication that can be taken to ease withdrawal.
  • Help them to seek out education for the family and for themselves as well as cognitive behavioral therapy.
  • Seek out a 12 step program.
  • Approach them with care and understanding. But never enable them in the use of meth.
  • Never approach them if they have been using and are currently “high” on the drug. Users can be very violent and unable to control their actions. This could put you in a dangerous position.
  • Try to introduce new activities or old activities that had been left behind because of the drug use.
  • Create happy and positive exchanges between the user and other people.
  • Try using positive reinforcement when the user abstains from using.
  • Let natural negative consequences happen if they begin to use again. This could be a loss of job, school, or friends.
  • Help them to find a treatment program so they don’t feel they have to do this on their own. (20)



Published on by under Addiction and Withdrawals.
Article was last reviewed on August 16th, 2016.

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