Skip to main content
. Author manuscript; available in PMC: 2013 Jul 21.
Published in final edited form as: Sports Med. 2011 Nov 1;41(11):949–966. doi: 10.2165/11591430-000000000-00000

Table I.

Cannabinoid excretion data based on creatinine-normalized urine concentrationsa

Variable Groups according to cannabinoid to creatinine ratio (ng/mg)
≤50 51–150 >150
Smoking frequency (d/mo) 2–30 6–30 12–30
History of cannabis smoking (y) ≤25 ≤22 ≤24
Mean time until first negative specimen (d) 0.6 3.2 4.7
Mean time until last positive specimen (d) 4.3 9.7 15.4
a

Sixty cannabis smokers resided on a closed research unit under 24-h monitoring for up to 30 d. All urine specimens were collected and individually analysed for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol.