How long does meth stay in your system?

Meth can stay in the body much longer than cocaine. So how long does meth linger in the system? How addictive is meth? We explore here.

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Reviewed by: Dr. Dili Gonzalez, M.D.

Meth can stay in the system and be detected in urinalysis drug tests 1-4 days after use. But chronic use can extended this detection period. More here on how meth works and the length of time it stays in your system, with a section for your questions about meth at the end.

What is meth?

Meth (short for “methamphetamine”) is a highly addictive stimulant that affects the central nervous system. While small doses of meth can be prescribed legally for limited medical uses, most recreational doses of meth are manufactured illegally.

How do you take meth?

Meth comes in different forms and can be taken in multiple ways. If prescribed, methamphetamine comes as a pill. In its powder form, meth can be ingested, snorted, or injected. In its “crystal” or rock form, meth can be smoked.

Main meth uses

Under the Controlled Substances Act, meth is classified as a Schedule II drug, which allows for very limited medical use. Medical professionals may issue a non-refillable prescription of methamphetamine as treatment for narcolepsy, attention deficit and attention deficit hyperactivity disorders, and obesity.

Recreationally, meth is used as a stimulant. Soon after smoking or injecting meth, the drug produces a short and intense rush. If ingested or snorted, meth can produce a longer high lasting about half a day. When used recreationally, meth creates a feeling of euphoria. However, in the U.S., it is illegal to possess meth without a prescription.

Peak levels and half-life of meth

Blood concentrations of meth vary depending on the amount taken. Since meth can be prescribed by medical professionals, there is a therapeutic level of blood concentration, which usually ranges from .02-.05 mg/L. Recreational meth use, on the other hand, can range from anywhere between .01-2.5mg/L. Concentrations above .2mg/L are associated with abuse, and the threshold for toxicity for meth is above 2.5mg/L.

Meth reaches peak levels in blood concentration differently depending on mode of administration. The half-life of meth can range greatly, but for all methods of administration the half-life ranges between about 10 and 12 hours. When ingesting meth, peak concentration of methamphetamine occurs in approximately three hours. For smoking and snorting, peak concentration takes between two and three hours.

Meth drug testing: How long does meth stay in the body?

Different drugs and their metabolites are stay detectable through drug testing for different amounts of time. Meth stays in the body much longer than some other drugs.

For example, 50% of cocaine leaves the body after only one hour. With a half-life of nearly twelve hours, meth stays in the system for a significantly longer period of time. The exact amount of time methamphetamine can stay in the body depends on a number of factors, such as urine pH levels, amount taken, how frequently the drug is used, body mass, rate of metabolism, or other circumstance.

How long does meth stay in blood?

Meth stays in the blood for approximately 24-48 hours.

How long does meth stay in hair?

The longest amount of detection time for meth is in hair. Once the hair grows out after use, meth can be found months or even years after the cessation of use. Presence of meth in hair depends on the level of meth usage and the length of hair. One half an inch of hair represents about 30 days in hair testing for meth.

How long does meth stay in urine?

Urinalysis can turn up a positive result for meth within 1-4 days, but heavy and/or chronic use can extend this time frame.

How long does meth stay in saliva or sweat?

Meth can stay in saliva for approximately 1-2 days. Evidence of meth use can be detected in sweat within two hours and sometimes over a week after someone has stopped using meth.

Meth and addiction

Meth is highly addictive. It is much less expensive than cocaine and produces a much longer high. Use of meth releases a large amount of neurotransmitters into the brain such as dopamine, a chemical involved in the brain’s reward circuit. The large amount of dopamine released during the meth rush depletes the brain’s supply and leads to a “crash,” including a depressive phase. Users often seek more meth to recreate the euphoria, leading to a cycle of addiction.

Are you worried that your meth use may be getting out of hand? Meth addiction is a treatable condition if you are willing to accept help. Learn more about Methamphetamine Addiction Treatment Programs and Help to be better prepared for what you can expect during the recovery process.

Let’s verify your coverage for treatment at an American Addiction Centers location. Your information is always confidential.


Problems with meth?

If you have a problem with meth, please seek the advice of a doctor. Otherwise, we invite you to ask questions or share your experiences in the comments below.

Reference Sources: NIDA: Drug Facts: Methamphetamine 
NIDA: Drug Abuse: Methamphetamine
DEA: Drug Data Sheets on Methamphetamine
NHTSA: Methamphetamine
PubMed: The bioavailability of intranasal and smoked methamphetamine
CDC Fact Sheets on Methamphetamine
PubMed: Methamphetamine Disposition in Oral Fluid, Plasma, and Urine 
PubMed: Excretion of Methamphetamine and Amphetamine in Human Sweat Following Controlled Oral Methamphetamine Administration
PubMed: Methamphetamine detection in maternal and neonatal hair: implications for fetal safety
About the author
Lee Weber is a published author, medical writer, and woman in long-term recovery from addiction. Her latest book, The Definitive Guide to Addiction Interventions is set to reach university bookstores in early 2019.
Medical Reviewers
Dr. Dili Gonzalez, M.D. is a general surgeon practicing women's focused medici...

All of the information on this page has been reviewed and verified by a licensed medical professional.

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