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Question

27 Nov 2004

marijuana in blood
Dear Doctor

Can you please tell me how long marijuana stays in the bloodstream for. How many days or weeks later can it show positive in a blood test?
Answer 369 views
Expert
pathologist

01 Jan 0001

Cannabis and its active ingredient THC is tested for in most drug tests. After one-off or occasional use its break-down products or metabolites can be detected between 3-5 days after use. However, THC can be detected in a chronic user up to 12 weeks after use although the average is 25 -27 days.

Cannabis is highly detectable a long time after use because THC lingers in the fatty tissues of the body and leaks steadily into the blood and then the urine over weeks.

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