Cannabis and the 150 threshold: why legal does not mean clear

In one study of regular users, subjects were still testing positive 28 days after they stopped. That is the whole problem, and it is why cannabis needs its own article rather than a line in a list.

The others in its category leave the body in days. This one does not, and that changes every practical question about it.

The rule

Cannabinoids sit in section S8 of the Prohibited List, prohibited in competition only. Cannabidiol was taken off the List and is not prohibited.

Delta-9 THC is the only cannabinoid with a threshold, and it is set at 150 ng/mL in urine, measured through the metabolite carboxy-THC. Below it, no adverse finding.

Above it, the laboratory must report a positive regardless of when the substance was used.

Laboratories apply a decision limit of 180 ng/mL to account for measurement uncertainty, so a sample is reported when it exceeds that figure.

Why 150, and what it was meant to do

The threshold used to be 15 ng/mL. WADA raised it tenfold in 2013, and it did so with a specific stated purpose: to reduce adverse findings caused by use that happened outside competition.

WADA's own position is that the level required to trigger a finding today would be consistent with a significantly impaired athlete or a frequent user.

That is a sensible design, and it deserves saying. The regulator was not trying to catch people for a weekend 2 months ago.

Whether it succeeds is a different question.

The part that does not behave

What the pharmacology does to that intention.

In one study of around 70 cannabis users, the average detection window came out at roughly 10 days. After 28 days, a number of them were still testing positive.

Figures vary between studies and protocols, and that variation is itself the finding rather than a flaw in the research.

And the finding underneath that one is stranger. The higher a subject's initial urine concentration, the longer it took to clear. But that initial concentration did not track how much they had used. Some who smoked several times a day landed in the low group.

Some who used far less landed high.

Which means the honest answer to "how long before I am clear" is that nobody can tell you from the dose. Not your coach, not me, not a chart on the internet.

Why this lands differently on a weight-class athlete

THC is stored in fat. Athletes with higher body fat clear it more slowly, which is documented and uncontroversial.

Now think about what a fight camp does. Eight weeks of deliberate fat loss, then an acute phase on top.

A fighter's body composition at the weigh-in is not the body composition he had when he last used anything.

Whether mobilising fat meaningfully changes what shows up in a sample is a question I cannot answer with a citation, and I am not going to pretend otherwise.

Ask it, and treat the answer as an unknown rather than as reassurance in either direction.

CBD, which is where clean athletes get caught

CBD is permitted. That is the sentence everyone remembers, and it is where the trouble starts.

CBD products made from cannabis plant extracts frequently contain THC. A 2017 analysis published in JAMA found that fewer than a third of CBD products were correctly labelled for cannabinoid content.

A 2021 study in Drug Testing and Analysis looked at what that means in practice. Under its protocol, cannabinoids were detected in 80% of urine samples collected 8 hours after CBD was applied.

Different products and doses will produce different numbers; the direction is what matters.

So an athlete using a legal, permitted compound, bought openly, can accumulate the prohibited one without any decision to use it. Same structure as every other contamination route: the label was wrong, and under strict liability the label is not your defence.

Different bodies, different rules

This is the area where the sport is least consistent, and a fighter needs to know which document applies to him rather than which headline he read.

Attitudes in some jurisdictions and some professional leagues have shifted considerably. WADA's position has not. An athlete under a Code-compliant programme is governed by the 150 ng/mL threshold whatever the law says where he lives, and a professional under a private programme may be governed by something else entirely.

Cannabis is legal in a great many places now. Legal and permitted are unrelated concepts, and confirming which programme governs your bout is the only way to know which one you are in.

Practical, for anyone who needs it

Do not calculate a washout from a dose. The relationship between how much was used and how long it takes to clear is not reliable enough to plan on.

If you need certainty, the honest interval is weeks rather than days, and even then individuals vary enormously.

Treat CBD as a supplement, not as a safe alternative. Third-party certification, a current certificate of analysis showing no THC, and a written record of the batch. Isolate rather than full spectrum.

Remember the sanction structure. THC is a substance of abuse, so out-of-competition use unrelated to performance carries 3 months rather than years, and one month with a treatment programme. A positive is still serious, and that structure is what makes it survivable.

The in-competition window opens at 11:59 p.m. the night before. Everything about the reduced sanction depends on which side of that line the use falls, and on being able to show it.

What I actually think about the rule

The scientific case that cannabis improves fight performance is not there, and I have not seen anyone serious argue it is.

What is there is a threshold designed to separate competition use from private life, applied to a substance whose clearance refuses to cooperate with that design. The result catches some people it was written for and some it was not, and the ones it was not written for are usually the least equipped to argue their case.

None of that argues for using it. What it argues for is knowing exactly where the line sits, because in this particular corner of the rules, the line is not where most fighters assume.