A CBD supplement left WADA-banned cannabinoids in urine, and exercise raised them

Cannabidiol occupies an unusual position in anti-doping. CBD itself is not prohibited by the World Anti-Doping Agency, but other cannabinoids that appear in "broad-spectrum" CBD products — cannabigerol (CBG) and cannabidivarin (CBDV) among them — remain prohibited [s1]. A study published this month in Medicine & Science in Sports & Exercise tested what that distinction means in practice for someone taking a commercially available product every day.

The design

Thirty-six healthy adults, 47% of them male, self-administered either a broad-spectrum CBD product at 150 mg per day — a product containing trace concentrations of CBG — or a visually identical placebo, for 10 weeks [s1]. Thirty-one were in the CBD group and five in the placebo group [s1].

That is a small placebo arm, and the study is not designed to detect a difference in any physiological outcome between groups. Its purpose is analytical chemistry: what shows up in urine and plasma, and at what rate.

After the 10 weeks, participants completed a fasted 90-minute bout of moderate-intensity exercise at 55% of peak oxygen uptake [s1]. Blood and urine were collected at baseline before supplementation began, and then before and after that exercise bout [s1].

What was detected

At baseline, no cannabinoids or metabolites were detected in either group [s1] — establishing that whatever appeared later came from the supplement.

After 10 weeks, urinary CBD and its metabolites (6-OH-CBD, 7-COOH-CBD and 7-OH-CBD) were present [s1]. More consequentially for an athlete subject to testing, CBG was detected in 42% of pre-exercise samples and CBDV in 68% [s1].

Then the exercise effect. Urinary concentrations rose significantly from pre- to post-exercise for 6-OH-CBD (P = 0.006), 7-OH-CBD (P = 0.009), CBD (P = 0.043), CBG (P = 0.0023) and CBDV (P = 0.033) [s1]. Detection rates rose with them: after exercise, CBG was detected in 74% of samples and CBDV in 84% [s1].

Δ9-THC and its metabolites 11-OH-THC and 11-COOH-THC were not detected at any timepoint [s1]. The product did not produce the cannabinoid most people associate with a positive cannabis test; it produced two others.

Why exercise would raise the numbers

The study reports the association, not a mechanism, and the abstract does not propose one. Plausible explanations include exercise-driven changes in fluid balance concentrating urine, and mobilisation of lipophilic compounds stored in adipose tissue during a fasted endurance bout. Which of these dominates is not established here.

What matters practically is the timing. Anti-doping samples are frequently collected immediately after competition — precisely the window in which this study found the highest detection rates.

The authors' conclusion

The paper concludes that daily use of a broad-spectrum CBD supplement resulted in detectable urinary concentrations of WADA-prohibited cannabinoids, that exercise appeared to increase those concentrations, and that athletes should therefore avoid consuming broad-spectrum CBD products given the associated anti-doping risks [s1].

That is the authors' recommendation, stated as they state it. This article does not offer guidance on what any individual should take; the finding is about what a product can put in a urine sample.

The limits worth naming

This is a single study of one commercial product at one dose over one duration, in 36 people who were not competitive athletes. It does not establish that any given broad-spectrum product on the market contains CBG or CBDV — the product tested here contained trace CBG, and formulations vary widely. It does not report whether the concentrations detected would exceed any analytical threshold used by an accredited laboratory in an adverse finding, and detection is not the same as a rule violation. And with five participants in the placebo group, it cannot speak to any effect of the supplement beyond what appeared in the samples.

The wider context

Interest in cannabinoids among athletes is not confined to recovery products. A narrative review published a few days later surveys the rising interest in cannabis and its derivatives as therapeutic tools to support brain health, particularly in athletes, and maps where cannabinoid and exercise effects overlap physiologically — through inflammation, vascular function and neuroplasticity [s2]. Its conclusion is deliberately unsettled: the review argues that interactions between the two have potential to be additive, synergistic or opposing, and that accounting for those interactions will be critical as cannabinoids are applied more widely in the sport sciences [s2].

Neither paper establishes that CBD products help athletes. What the MSSE study establishes is narrower and more immediately actionable: a legal supplement, taken as directed, put prohibited substances in urine, and the standard post-competition testing window is when they were most likely to be found [s1].

What to watch

Whether product-testing and certification schemes for supplements begin screening specifically for CBG and CBDV rather than only for THC. The gap this study exposes is not that athletes are taking something banned — it is that a product marketed on the legality of one cannabinoid can carry two others.

Sources

• 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 & Science in Sports & Exercise, 2025-09-08
• Considering the Effects of Cannabinoids and Exercise on the Brain: A Narrative Review — Sports (Basel), 2025-09-11