Terminal elimination plasma half-life of delta 1-tetrahydrocannabinol (delta 1-THC) in heavy users of marijuana

Eur J Clin Pharmacol. 1989;37(3):273-7. doi: 10.1007/BF00679783.


The terminal elimination half-life of delta 1-tetrahydrocannabinol (delta 1-THC) was investigated in eight men who were heavy users of marijuana. A stable isotope assay, following smoking deuterium-labeled delta 1-THC, was used to determine plasma concentrations. In two additional users plasma levels were followed after administration of unlabeled delta 1-THC. The subjects were asked to smoke a "loading dose" of 56 mg delta 1-THC during two days and then abstain from all marijuana use for 4 weeks. The pharmacokinetic behavior was consistent with a multicompartment model with a mean plasma elimination half-life of delta 1-THC of 4.3 days when concentrations were followed for 10-15 days after smoking. In the two subjects with detectable plasma levels during 4 weeks, half-lives of 9.6 and 12.6 days was obtained.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Dronabinol / blood
  • Dronabinol / pharmacokinetics*
  • Dronabinol / urine
  • Half-Life
  • Humans
  • Immunoenzyme Techniques
  • Male
  • Marijuana Smoking / blood*


  • Dronabinol