Hi, There has been so much discussion about this very subject in just the last few days and there are a few threads just below this one about blood. I personally have come to the conclusion that below is as close as I can find....


Cannabis......BLOOD......SALIVA......SWEAT........ URINE HAIR

(single use)..2-3 days....12-24 hrs...unknown......2-3 days up to 90 days

(habitual use)2 weeks....12-24 hrs...unknown......up to 12 wks up to 90 days