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How Long Does Marijuana Stay In Your System

Recreational and medicinal marijuana use is becoming legal in several states, and many people believe that it will be legal in every state within the next 10 years. Regardless of its legality, situations in states like Colorado where weed is legal to buy and use have shown that employers and other government agencies do not have to be more lenient with their hiring practices for those that partake. If you smoke pot, there is a very good chance that you will suffer negative consequences at some time in your life due to a failed drug test. When it comes to things like your career, education or freedom, it’s not worth the risk.


There are several factors to consider regarding the amount of time it will take to pass a drug test after smoking marijuana.


A medical marijuana dispensary in Colorado. Despite legalization, employers and certain government agencies still test for THC.


Type of Test

Employers conduct 50 million drug tests every year, and even though there are standards it is impossible to know which testing method or what cutoff levels an employer will use without prior knowledge. In most cases employers will use urine testing or saliva testing, however hair follicle testing and blood testing is common in certain industries.


Each method exposes the employee to different detection windows. Although the types of drugs included in each test vary, they will almost certainly test for THC. Since THC is fat soluble and not water soluble, it is stored in fatty tissue in the kidneys and can be detected for a much longer period than other types of drugs.


Oraquick saliva drug test is becoming popular with some employers.


Body Fat & Metabolism

It has been well documented that chronic users take much longer to expel detectable levels of THC from their body. Due to the fat solubility of THC, users with a higher BMI and slower metabolism will test positive for THC for longer than users with a faster metabolism.




Common Detection Periods


  • Single Use: 1-2 Days
  • Chronic Use: 1-7 Days

Hair: Most standard hair testing methods take 1.5″ from your scalp, which will exhibit drug use from 3 days prior to roughly 100 days prior. THC does not always bind to the hair follicle.

Saliva: 12-36 Hours

Urine: The most common method of testing also has the widest window of detection. For most users THC will be detectable for 3-14 days. For chronic users or users with a slow metabolism, it could be closer to 28 days and there have been reports of THC showing up in urinalysis for 100 days after use.


Cheating the Test

There is one surefire way to pass a drug test, and that is to not use illicit substances. Many companies claim to sell products that will fool a drug test and there are lots of sources online with recommendations about how to trick the test, but most urine tests have control lines and validity panels that test for adulterants, creatinine levels, temperature levels and specific gravity. Still other companies sell prosthetic devices that hold a clean urine sample and imitate giving a real sample, but most drug tests will be supervised and the proxy will be trained in spotting such devices. Any test that shows signs of tampering is an automatic fail in most cases, and may preclude the potential new hire from ever applying again. Most larger companies will allow an applicant that failed for THC to re-apply in 6 months to a year, so the penalty for trying to cheat the test will most certainly be stiffer than for someone that simply failed the test.


If you suspect that you may have to take a drug test for employment and think you have THC in your system, quit using immediately and drink 6-8 glasses of water per day until the test. Drink a normal amount of water on the day of the test as it will dilute your sample, but be careful not to consume too much or your sample will be clear and your creatinine will be outside of normal levels. This will not make you pass it any quicker (THC is fat soluble, not water soluble) but will ensure that you will not fail a test that your normally wouldn’t have because your urine has a higher concentration of cannabinoid metabolites than normal.


You can order a 12 Panel Drug Test from our web store to confirm that you will past the test you expect to be given by your employer.


The cutoff level for most standardized urine tests is 50ng/mL for THC.  Urine tests detect a metabolite of THC, THC-COOH.



For most recreational users of marijuana, you can expect to pass a urine screen 7-14 days after your last use. For heavy users and users with a higher body fat content, it could take 30 days or more to clear your system of the metabolite that is screened for in a standard urine drug screen.




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