EVIDENCE LIBRARY
Oral Cannabis Pharmacokinetics: Why Testing Time and Specimen Matter
A controlled oral-cannabis study measured blood and oral-fluid cannabinoid concentrations after brownies containing 10, 25, or 50 mg THC.
Research summary
A controlled oral-cannabis study measured blood and oral-fluid cannabinoid concentrations after brownies containing 10, 25, or 50 mg THC. Subjective and cognitive effects were generally dose-dependent and peaked later than would be expected from rapid inhalation. Early oral-fluid THC values may reflect residue in the mouth rather than systemic drug exposure. Concentration, collection time, analytical cutoff, and route of administration should therefore be reported before an inference about recent use or impairment.
Forensic interpretation
This research describes specific experimental conditions. It does not establish an individual driver’s impairment or the cause of an observed clinical finding without case-specific information. Analytical methodology, timing, dose, route of administration, and plausible alternative explanations should be assessed before making a forensic inference.