The age-old question: "How long does weed stay in my body?" this thought runs over and over in your head, knowing that you will have a drug test in the next couple of days or even tomorrow. To get to the bottom of this, you will need to understand the four methods of drug testing, and how each can detect THC in your system for certain time periods.
This is the most common drug screening method. This test is the most common because it is able to detect THC in your system from as long as 100 days prior. But many things can affect this, including your personal metabolism, how heavy of a smoker you are, and how sensitive you are to the test. In 2005, Dr. Paul Cary, the director of the Toxicology and Drug Monitoring Laboratory at University of Missouri, found that "it would be unlikely for a chronic user of marijuana to produce a positive urine drug test result for longer than 10 days after the last smoking episode," but this could be extended to around 21 days for more frequent users. On the other hand, for those have smoked for the first time or 2-4 times a month, "it would be unusual for the detection of cannabinoids in urine to extend beyond 3-4 days following the smoking episode." said Cary.
Chronic Smokers: Will be detectable in your system between 10-21 days
First-Time & Occasional Smokers: Will detectable in your system between 3-4 days
Most commonly used by police officers issuing DUI's and jobs issuing random on-site testing, this screening can only detect THC in the system for the past 12 hours.
Chronic, First-Time, & Occasional Smokers: Will only detect THC in your body within the past 12 hours.
This method of drug testing for marijuana is not very common. It is similar to the saliva drug testing method because it can only detect THC for a short time period - 2 days. Most commonly used by police officers who are testing to see if a user is impaired.
Chronic, First-Time, & Occasional Smokers: Will only detect THC in your body within the past 2 days.
This is the scariest of the drug tests, allowing for detection of THC up to 8x farther back than a urine drug test. THC is detectable for up to one year, and at the least 6 months! Even if you have stopped smoking for a couple months, a hair drug test will still show up positive.
Chronic, First-Time, & Occasional Smokers: Will detect THC in your body hair from 6 months to 1 year.