Plasma cannabinoid pharmacokinetics following the inhalation of vaporised cannabis with and without cannabidiol.
Daniel L. Hall, Edward Chesney, Claire Mokrysz, Anna Caldwell, John Halket, Kat Petrilli, Matthew B. Wall, H Val Curran, Tom P. Freeman, Will Lawn
Drug and Alcohol Dependence July 1, 2026 DOI: 10.1016/j.drugalcdep.2026.113160 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomised, double-blind, placebo-controlled, cross-over study Randomized Peer reviewed |
|---|---|
| Sample size | 48 |
| Population | Adolescents aged 16-17 years and adults aged 26-29 years |
| Interventions | THC+CBD placebo |
| Dose | 8 mg THC/75 kg (THC-alone); 8 mg THC and 24 mg CBD/75 kg (THC+CBD) |
| Topics | Cannabis CBD |
| Keywords | Adolescent Cannabinoid Inhalation Pharmacokinetic Plasma |
| Key points | The THC+CBD vaporised cannabis condition produced significantly greater plasma levels of THC, OH-THC, and COOH-THC than the THC-alone condition, measured by natural-log-transformed area-under-the-curve and peak concentration, except for OH-THC peak concentration. The authors report no strong evidence of age-related differences in cannabinoid pharmacokinetics between adolescents and adults. |
Abstract
The presence of cannabidiol (CBD) in cannabis may alter cannabinoid pharmacokinetics, however previous research has produced mixed results. Furthermore, no prior research has explored how cannabinoid pharmacokinetics are moderated by age. Using vaporised and inhaled cannabis, we aimed to (1) examine the effect of CBD on the plasma concentration of delta-9-tetrahydrocannabinol (THC) and its metabolites, and (2) compare cannabinoid plasma pharmacokinetics in adolescents and adults. We conducted a randomised, double-blind, placebo-controlled, cross-over study. We compared the effects of three vaporized, weight-adjusted cannabis preparations: 'THC-alone' (8mg THC/75kg), 'THC+CBD' (8mg THC and 24mg CBD/75kg) and placebo, in 48 participants, aged 16-17-years and 26-29-years. Blood samples were taken prior to inhalation, then 20, 30, and 160min after inhalation began. Thirty-five participants had complete pharmacokinetic datasets, which were analysed. Plasma was analysed for concentrations of THC, 11-hydroxy-THC (OH-THC) and 11-Nor-9-carboxy-THC (COOH-THC), CBD, 7-hydroxy-cannabidiol (OH-CBD) and 7-carboxy-cannabidiol (COOH-CBD). The 'THC+CBD' condition produced significantly greater THC, OH-THC, and COOH-THC plasma levels than the 'THC-alone' condition, in terms of natural-log-transformed area-under-the-curve (AUC) and peak concentration (Cmax) values, with the exception of Cmax for OH-THC. Geometric mean ratios showed the 'THC+CBD' condition led to higher THC plasma levels. There was no strong evidence of age-related differences. The presence of CBD in vaporised cannabis increased circulating levels of THC and THC-metabolites. However, further research is needed to understand discrepancies across studies regarding the impact of CBD on THC pharmacokinetics.
Comparable studies
Other randomized controlled trials on CBD, most cited first.
Citations in the library
Cites 6
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- The acute effects of cannabis with and without cannabidiol in adults and adolescents: A randomised, double‐blind, placebo‐controlled, crossover experiment Addiction February 8, 2023
- Acute effects of different types of cannabis on young adult and adolescent resting-state brain networks Neuropsychopharmacology May 28, 2024
- Assessment of Orally Administered Δ9-Tetrahydrocannabinol When Coadministered With Cannabidiol on Δ9-Tetrahydrocannabinol Pharmacokinetics and Pharmacodynamics in Healthy Adults: A Randomized Clinical Trial. JAMA Network Open February 1, 2023
- Does cannabidiol make cannabis safer? A randomised, double-blind, cross-over trial of cannabis with four different CBD:THC ratios Neuropsychopharmacology November 16, 2022
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