Ten weeks of daily broad-spectrum CBD supplementation produced detectable levels of WADA-prohibited cannabinoids in urine, with concentrations increasing after exercise.
Athletes considering CBD supplements, sports medicine professionals, anti-doping officials, and anyone interested in CBD product regulation.
What the researchers found
Daily use of a broad-spectrum CBD product (150 mg/day) led to detectable urinary concentrations of CBG in 42% and CBDV in 68% of pre-exercise samples, rising to 74% and 84% post-exercise, despite no THC detection at any timepoint.
Why it matters
Athletes using legal broad-spectrum CBD products may unknowingly test positive for prohibited cannabinoids under WADA rules, and exercise amplifies this risk — a critical finding for competitive sport.
The numbers in context
150 mg/day CBD for 10 weeks; n=36; CBG detected in 42→74% of samples pre-to-post exercise; CBDV in 68→84%; significant post-exercise increases for CBD (p=0.043), CBG (p=0.0023), CBDV (p=0.033); zero THC detection
How the study worked
Randomized, placebo-controlled trial with 36 healthy individuals (31 CBD, 5 placebo) self-administering broad-spectrum CBD or placebo for 10 weeks, followed by a 90-minute moderate-intensity exercise bout with blood and urine sampling.
What this study cannot tell us
Small placebo group (n=5); single CBD product tested; exercise protocol was moderate intensity only; did not assess high-intensity or repeated exercise effects; short-term study without washout period assessment.
How to read the evidence
Randomized placebo-controlled design with objective biomarker outcomes, though limited by small sample size and single product tested.
When this study was published
Published 2026; reflects current CBD product formulations and WADA prohibited list.
The bigger picture
As CBD use grows among athletes for recovery and wellness, this study reveals an underappreciated anti-doping risk from trace cannabinoids in broad-spectrum products that regulators and sports organizations need to address.
Questions still open
- Would isolate CBD products avoid this risk entirely? How long after stopping supplementation do prohibited cannabinoids remain detectable? Does exercise intensity correlate with cannabinoid release?
Common questions
Can CBD supplements cause a failed drug test in sports?
Does exercise affect CBD drug test results?
Read the original research
Daily Use of a Broad-Spectrum Cannabidiol Supplement Produces Detectable Concentrations of Cannabinoids in Urine Prohibited by the World Anti-Doping Agency: An Effect Amplified by Exercise.
Medicine and science in sports and exercise, 58(1), 121-131
Citation
Gillham, Scott H; Cole, Paige L; Owens, Daniel J; Chester, Neil; Bampouras, Theodoros M; McCartney, Danielle; Gordon, Rebecca; McGregor, Iain S; Close, Graeme L. (2026). Daily Use of a Broad-Spectrum Cannabidiol Supplement Produces Detectable Concentrations of Cannabinoids in Urine Prohibited by the World Anti-Doping Agency: An Effect Amplified by Exercise.. Medicine and science in sports and exercise, 58(1), 121-131. https://doi.org/10.1249/MSS.0000000000003842
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