Urinary CBD Peaks Differed After Oral and Vaporized Dosing
The same nominal CBD dose produced different urinary profiles after oral and vaporized administration in a controlled human study. Those profiles describe excretion under the study conditions; they do not provide a reliable clock for an individual’s last use or an impairment threshold.
The specimen was urine
The study examined 18 healthy adults receiving 100 mg CBD by oral administration or vaporization, as well as vaporized CBD-dominant cannabis containing 100 mg CBD and 3.7 mg THC. Investigators collected urine before dosing and for 58 hours afterward on a residential research unit.
The oral formulations included a capsule, a pharmacy-grade syrup and Epidiolex, with six participants per formulation. A fasting comparison involved only six participants. These small formulation groups deserve more caution than the overall participant count might suggest.
Parent CBD appeared on different schedules
Mean peak urinary CBD was 734 ng/mL after oral administration and 240 ng/mL after vaporized CBD. Mean time to peak was 4.7 hours orally and 1.3 hours after vaporization. These are group summaries of urine measurements, not plasma exposure values, delivered-dose estimates, or guaranteed detection windows.
Formulation and between-person variability complicate interpretation. Urine is collected over an interval, and the study’s treatment of collection timing must be considered before comparing a reported urinary peak with an instantaneous blood draw.
THC-containing material is a separate question
After the CBD-dominant cannabis condition, three of 18 participants produced specimens with THCCOOH at or above the study’s 15 ng/mL confirmation threshold. Screening outcomes depended on the immunoassay cutoff. Pure-CBD conditions did not provide evidence of conversion to THC. These observations should not be merged into a claim that CBD itself necessarily causes a positive THC test.
The report incorporated participants from an earlier pilot, so the pilot and expanded paper should not be counted as entirely independent replications. Single-dose findings also cannot guarantee the outcome of repeated retail-product use.
When reviewing a test, identify the analyte, route, product composition, collection interval and decision cutoff. Exposure evidence and functional effects remain distinct, as explained in our discussion of concentration and impairment.
Primary research
Dennis J Sholler and colleagues. Journal of Analytical Toxicology (2021). Urinary Pharmacokinetic Profile of Cannabidiol (CBD), Δ9-Tetrahydrocannabinol (THC) and Their Metabolites following Oral and Vaporized CBD and Vaporized CBD-Dominant Cannabis Administration.
