Marijuana-laced brownies: behavioral effects, physiologic effects, and urinalysis in humans following ingestion

J Anal Toxicol. Jul-Aug 1988;12(4):169-75. doi: 10.1093/jat/12.4.169.


Five drug-free male subjects ingested marijuana-laced brownies in a double-blind crossover study designed to test for behavioral effects, physiologic effects, and urinary cannabinoid metabolites produced as a result of consumption of marijuana plant material cooked in foodstuff. On three separate occasions, each subject consumed two brownies which contained 1.6 g of marijuana plant material. Placebo marijuana plant material (0% THC) was mixed with marijuana plant material (2.8% THC) so that each subject ingested equivalent marijuana plant material of 0, 1, and 2 marijuana cigarettes (2.8% THC). Subjects scored significantly higher on behavioral measures after consumption of brownies containing THC than with placebo; however, the effects were slow to appear and variable. Peak effects occurred 2.5 to 3.5 h after dosing. Modest changes in pulse and blood pressure also were noted. Urinalyses by EMIT d.a.u. assay and Abuscreen RIA for cannabinoids and GC/MS assay for THCCOOH indicated that substantial amounts of marijuana-related metabolites were excreted over a period of 3 to 14 days. No positives were produced as a result of ingestion of placebo brownies.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Behavior / drug effects*
  • Blood Pressure / drug effects
  • Cannabinoids / urine*
  • Cannabis*
  • Double-Blind Method
  • Food
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Male
  • Marijuana Smoking
  • Radioimmunoassay
  • Random Allocation


  • Cannabinoids