THC-COOH Thresholds & Windows: 35, 150, 350 ng/mL Explained

The 15 → 150 ng/mL Threshold Story Strong evidence

For most of anti-doping's history, WADA's urinary THC-COOH threshold sat at 15 ng/mL. The number was an analytical-detection floor, not an evidence-based impairment threshold. Out-of-competition users were routinely caught for use that had nothing to do with competition itself. Effective May 2013, WADA raised the threshold tenfold to 150 ng/mL. WADA Director of Communications Julie Masse described the goal as focusing "on the athletes that abuse the substance in competition." The empirical result confirmed the diagnosis: the percentage of failed cannabis tests under WADA's program dropped from 9.0% in 2012 to 2.4% in 2014. The change did not reduce in-competition use; it stopped catching out-of-competition use that had been caught only because the prior threshold was too low.

WADA's accredited laboratories also apply a 180 ng/mL Decision Limit — the threshold a sample must actually exceed for the lab to report an Adverse Analytical Finding (AAF), built to absorb measurement uncertainty. A result of 165 ng/mL is technically above the 150 ng/mL threshold but below the 180 ng/mL Decision Limit and is not reportable as a positive.

League-by-League Thresholds in 2026

The arc is unmistakable: every body that has revisited its threshold this century has raised it. The 15 ng/mL number that defined a decade of athlete cannabis enforcement is now used by no major program.

Detection Windows by Test Matrix

Detection windows are shaped by what each matrix actually measures. Urine measures THC-COOH (the inactive, fat-soluble metabolite); blood measures parent THC (the active, fast-clearing molecule); oral fluid measures parent THC at the mucosa; hair captures cumulative cannabinoid deposition during follicle growth.

• Urine — days to several weeks for THC-COOH. Light users typically clear below 150 ng/mL within 1–2 weeks; moderate-to-heavy daily users can remain above 150 ng/mL for 3–6 weeks. Re-mobilization from adipose tissue under fasted training or weight cuts can extend the window further (Wong et al., Drug Testing and Analysis, 2013).
• Blood — parent THC for hours, occasionally up to two days in heavy chronic users.
• Oral fluid (saliva) — parent THC for roughly 24 hours; the closest matrix to a recency proxy.
• Hair — approximately 90 days, depending on hair length and growth rate.

Why Threshold Choice Matters More Than It Sounds

A 15 ng/mL threshold catches almost any cannabis use within the prior month. A 150 ng/mL threshold catches use within the prior days to about two weeks for most users. A 350 ng/mL threshold — the NFL's number since December 6, 2024 — functionally catches only fairly recent or fairly heavy use. Each step up the threshold shifts the policy posture: from "we test for any prior use" toward "we test for use that overlaps the competitive window." The NFL, NCAA Division I, and WADA have moved through that policy spectrum at different speeds, but in the same direction.

For the practical implications, see In-Competition vs Out-of-Competition and Cannabis Washout Protocols. For the WADA in-competition framework specifically, see WADA & Olympic Rules.