Sex-Related Cannabis Concentration Patterns Changed With the Sample Matrix
The direction of the reported sex-related concentration pattern differed between blood and oral fluid in this small inhaled-cannabis study. That finding cautions against describing a single universal female–male difference in cannabis exposure.
The comparisons were descriptive
The study included nine men and eight women who had not used cannabis during the preceding month. The authors described qualitatively higher average peak whole-blood THC and 11-OH-THC concentrations among women at the tested doses and inhalation methods.
They also noted a potential influence of body weight: men averaged approximately 85 kg and women approximately 70 kg. The fixed nominal THC doses were not a design that isolated sex independently of every other contributor to concentration.
Oral fluid showed a different pattern
Mean peak oral-fluid THC was qualitatively higher among men. The authors linked this pattern to several male participants with extremely high oral-fluid THC despite little or no whole-blood THC.
This matters because oral-fluid THC after inhalation can reflect drug remaining in the mouth as well as processes governing systemic exposure. Reversing the matrix changed the descriptive comparison; it did not establish that one sex was consistently more impaired.
What the report can support
These small subgroup summaries are a reason to retain matrix, timing, body-size context and individual variability. They do not establish sex-specific legal limits or universal dose adjustments. The paper and its companion acute-effects trial concern the same seventeen-person experiment, so their findings should not be counted twice as independent evidence.
Related analysis: blood and oral-fluid patterns after inhaled cannabis.
Research cited
Spindle and colleagues (2019), Acute Pharmacokinetic Profile of Smoked and Vaporized Cannabis in Human Blood and Oral Fluid. DOI: 10.1093/jat/bky104.
