Marihuana: studies on the disposition and metabolism of delta-9-tetrahydrocannabinol in man.

Delta(9)-Tetrahydrocannabinol (the major active component of marihuana) administered intravenously to normal human volunteers persists in plasma for more than 3 days (t(1/2) = 56 hours). Its metabolites appear in plasma within 10 minutes after administration and persist along with the precursor compound. Delta(9)-Tetrahydrocannabinol is completely metabolized in man, and the radioactive metabolites are excreted in urine and feces for more than 8 days.