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Smoking and Tobacco

Detection

08/29/2000

Question:

how long after marijuana is inhaled can it be detected in blood and urine

Answer:

The focus of this Netwellness section is cigarette smoking. However, in response to your question, answers can be identified in the National Institutes of Health 1997 publication of a Workshop on the Medical Utility of Marijuana. Venous blood levels of THC drop quickly after smoking has ended. THC from blood is then distributed to other tissues in the body and is slowly released and metabolized. This results in a relatively long elimination time of from 20 hours to as long as 10-13 days. A study in the Journal of Analytical Toxicology (1996) identified peak urine concentrations of a metabolite (breakdown product)of THC between 5 and 28 hours after use. Levels are obviously related to the amount of THC taken into the body and individual variation in metabolism.

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Response by:

Karen L Ahijevych, PhD, RN, FAAN Karen L Ahijevych, PhD, RN, FAAN
Professor, College of Nursing
Professor, College of Public Health
College of Nursing
The Ohio State University