Methamphetamine, better known as meth or crystal meth, is a potent illicit central nervous system stimulant that is smoked or injected for its euphoric effects. While the effects of meth are often short-lived, traces of it can linger for much longer in the body's system.
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How long does meth stay in your system? At a glance
These are the average detection times for methamphetamine by test type in the average adult body.
|Type of drug test||Detection time|
|Urine testing||up to four-seven days|
|Blood testing||up to three day|
|Saliva testing||up to four days|
|Hair testing||up to 90 days|
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What is the half-life of meth?
Methamphetamine, commonly known as meth, has a half-life of around 10 hours in most people. While meth’s half-life and high may be short-lived, traces of the substance can stay in the system for far longer.
Meth detection times by method of drug testing
Different methods of drug testing are able to detect meth over different lengths of time. Some are more accurate than others while some have longer detection windows.
How long does meth stay in saliva?
Saliva tests are rarely used as substances tend to be hard to trace after a short amount of time. The presence of methamphetamine is detectable 10 mins after last use in saliva and for up to four days.
How long does meth stay in hair?
Hair follicle testing takes longer to process and is more expensive than other drug tests but can trace substance use back much further and more accurately. Meth is detectable in hair follicles up to 90 days after the last dose.
How long does meth stay in blood?
The presence of meth is detectable in blood tests within a few hours of last use and can be traced for up to three days.
How long does meth stay in urine?
Most urine tests will detect meth up four days after last use, though it can be detected up to seven days later in heavy users.
Factors that affect meth detection times
There are many factors that can influence the detection rate of illicit drugs in a toxicology test and these can vary from person to person.
Factors that influence meth detection rates include:
- Length of time meth was abused for (a chronic meth user will have larger traces of the drug in their system)
- Quantity of meth used (the concentration of meth in the system will be higher after a meth binge)
- Purity of the drug
- Fitness (physical activity can speed up the metabolism of meth)
- Whether other substances were taken (such as alcohol or other stimulants)
- Body mass index (obese people will take longer to process meth)
- Pre-existing medical conditions (especially those involving liver, heart, and kidney function)
Is there a risk of a false-positive drug test result for meth?
Urine tests, or immunoassays, is the most common form of drug testing used in the U.S. as they are cheap, easy to use and provide quick results.
For meth testing, immunoassays have a drawback that makes them occasionally inefficient. Many substances have similar detectable characteristics to methamphetamine that can be picked up in a urine test, even if the person being tested has never taken the drug.
This is known as a false-positive result, where the drug has been detected even though it isn’t in the body’s system. Drugs that can have an effect on meth urine tests include:
Antibiotics - Levaquin (levofloxacin) and Cipro (ciprofloxacin)
CNS stimulants - Ritalin (methylphenidate) and Adderall (dextroamphetamine-amphetamine)
Decongestants - Sudafed (pseudoephedrine)
Antipsychotics - Thorazine (chlorpromazine)
Blood pressure control medicine - Trandate (labetalol)
Oral diabetes medicine - Glucophage (metformin)
Antidepressants - Prozac (fluoxetine), Zoloft (sertraline), trazodone
When having a drug test for methamphetamine, it is important to notify the clinician if you have had any of the above substances. This way a more accurate drug test can be conducted.
Can I get meth out of my system quickly?
There are many claims on the internet for quick fixes to get meth out of your system quickly. Not only are these false, but some are also potentially life-threatening.
A “baking soda bomb” is a concoction of water, baking soda, and bleach that is reported to clear methamphetamine out of the system through urine. This recipe is unproven and incredibly dangerous as consuming bleach can cause liver, kidney, and intestinal damage as well as death.
The only way to get meth out of your system is to let it metabolize naturally and be passed in urine.
Meth addiction treatment
Meth is an incredibly potent stimulant that holds a high potential for abuse, dependence, and addiction. The drug is also cheap and readily available in many areas, making it even more likely for people who try it to become addicted.
Related: How much does meth cost?
If you or someone you care about is abusing meth and may have developed a dependence, it is important to seek out professional treatment before addiction occurs.
Getting treatment from a rehab facility can help to get meth and other drugs out of your system and regain control of your life. Visit our rehab directory to find a rehab center near you.