One Controlled Smoking Session Produced No Detectable Urinary Analytes
One occasional user had no detectable urinary analytes after an active smoking session. The authors proposed low effective intake from smoking behavior as an explanation, rather than treating nominal THC content as proof of a uniform absorbed dose.
The nominal dose was known
The study compared administration routes using cannabis material containing 50.6 mg THC. For one occasional participant’s smoking session, all measured urinary analytes were undetected. The report excluded that session from several concentration and timing summaries because those parameters could not be derived from a detectable profile.
The explanation was not a measured dose
The authors discussed smoking topography: puff number, duration, spacing and inhalation depth could influence actual intake. That is a plausible explanation for the unexpected result, not a direct measurement establishing how much THC entered that participant’s circulation. Other participants’ detection patterns should not be used to fill in the missing absorbed-dose value.
Why the exclusion matters
A peak-concentration summary based on detectable profiles does not describe every active session equally. When using the study to support a detection claim, retain the nondetectable session and the resulting denominator. The finding neither proves that cannabis never produces urinary evidence nor guarantees that every known smoking event must test positive under the same analytical criteria. It also provides no individualized conclusion about impairment.
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.
