The amount of time that your body retains traces of marijuana depends on a number of factors, including how often you smoke and your metabolism rate.
How Long Does THC Stay In Your System
Urine testing, or urinalysis, is the most common way of screening for marijuana use. In the United States, current and future employers will often ask you to undergo a urine test.
But how long will marijuana show up in your urine after you stop smoking? Unfortunately, the only accurate answer is: It depends.
THC vs. THC-COOH
THC is the active ingredient in marijuana and the chemical responsible for the high. However, urine tests detect a different chemical called THC-COOH.
Length of Detection Period
No one can really say how long you will test positive for marijuana, since the rate of THC metabolism varies per individual. The amount of marijuana consumed can also alter the window of time that your body retains traces of THC.
Someone who smokes occasionally – or for the first time – will likely test positive for 1-3 days afterward, according to a review by the National Drug Court Institute (NDCI).
Studies suggest someone who smokes often can expect to test positive for around a week following last use. According to the NDCI, after 10 days, most frequent users should pass a urine test at the 50 ng/mL threshold.