Concentrations of Delta 9-tetrahydrocannabinol (THC) in oral fluid at different time points after use

Published: 19 June 2024| Version 1 | DOI: 10.17632/ctr8g6gtny.1
Scott Macdonald,


This data is a meta-analysis of 7 studies where subjects were administered natural cannabis in a controlled setting, with Oral Fluid (OF) drug tests showing the exact THC concentrations in OF for each subject for at least two time points after cannabis administration using confirmatory methods. Summary statistics showed OF THC concentrations by time after use were highly dispersed at every time point, positively skewed, and declined over time. Many positive THC OF concentrations were found after 24-hours in one study, but most studies did not conduct observations past 24 hours. In a multivariate analysis, we found that increased dose, increased frequency of cannabis use, and inhaled (versus ingested) cannabis were statistically related to higher OF THC concentrations. OF collection device (i.e. intercept DOA versus expectorant) and sex (i.e. male versus female) were only significant in a bivariate analysis.


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A meta-analysis of studies from two databases (PubMed and Scopus) was conducted to produce 7 eligible studies


University of Victoria