A product can be described as CBD-rich and still deliver THC. In a controlled observation by Gerace and colleagues, one participant smoked a CBD-rich joint daily for 26 days. Each joint contained about 15 mg CBD and 0.5 mg THC. The investigators collected serial urine samples and measured THC-COOH, a metabolite of THC.
The researchers could quantify urinary THC-COOH after eight days. By day 15, a specimen collected 12 hours after the preceding intake exceeded the study’s 15 ng/mL cutoff. The dose, repeated use, collection timing and cutoff all matter when interpreting that observation.
The study shows that this exposure pattern was sufficient in one participant. It offers no estimate of how often others would cross the same threshold. A forensic review of a similar result would need the actual product composition, the exposure history and the laboratory’s reporting criteria.