Urinary THCV-COOH Detection Depended on Route and Participant

THCV-COOH was detected inconsistently across people and administration routes. Its absence could not be treated as a reliable exclusion of cannabis use in this controlled experiment.

Parent compound and metabolite differed

The study found no urinary THCV but did measure its carboxy metabolite, THCV-COOH. Among occasional users, no urine specimen was positive for that metabolite after smoking, and only two specimens from one participant were positive after vaporization. Every occasional participant had at least one detectable specimen after oral dosing.

Frequent use did not eliminate variability

The frequent-user group also showed participant-dependent findings. Some participants had no detectable THCV-COOH after smoking or vaporization, while other individuals had many positive specimens. Oral administration produced at least one positive specimen in each frequent user. These patterns describe the supplied cannabis material, route and observation conditions, not a universal marker sensitivity.

What a proposed marker must establish

A marker intended to exclude a product or route must be evaluated for how often it is absent despite known exposure. Analytical capability is only one part of that question. The small controlled human sample demonstrates why parent THCV, THCV-COOH and other cannabinoids should be named separately. None of these urine findings supplies a validated measure of driving impairment or identifies every commercial cannabis formulation.

Related analysis: the route-specific urine-model findings.

Research cited

Huestis and colleagues (2020). Free and Glucuronide Urine Cannabinoids after Controlled Smoked, Vaporized and Oral Cannabis Administration in Frequent and Occasional Cannabis Users. DOI: 10.1093/jat/bkaa046.