How long does it take the body to eliminate THC?

Cannabis was listed in the United States Pharmacopeia from 1850 until 1942, however the United States federal government does not currently recognize any legitimate medical use. (See also DEA). Regardless, Francis L. Young, an administrative law judge with the Drug Enforcement Agency, has declared that "in its natural form, (cannabis) is one of the safest therapeutically active substances known" .