Traces of marijuana stay in the body for several days after use. If a person has been using marijuana heavily, it can take weeks for the traces to be eliminated from the body.
Marijuana detection times
Blood/Saliva: In blood or saliva, marijuana can be detected for a few hours.
Urine: In urine, marijuana can be detected from 13 to 90 days depending on the amount of usage.
Hair: In hair, marijuana can be detected up to 90 days after usage.