Marijuana Δ9-Tetrahydrocannabinol (THC)
The parent drug, Δ9-tetrahydrocannabinol (THC), has a clearance half-life of less than 30 minutes and is not detectable in urine. Following a dose of THC, the metabolite typically appears in the urine within 60 minutes, but can take as long as 4 hours.
Note: The presence of the major THC-COOH > LOQ indicates exposure to THC within 3 days after a single use, to approximately 30 days in heavy chronic users.
- The major metabolite is tetrahydrocannabinol carboxylic acid (THC-COOH). THC-COOH is inactive and very lipid soluble.
Δ9-tetrahydrocannabinol (THC) → tetrahydrocannabinol carboxylic acid (THC-COOH)
Approximate Detection Times
|Marijuana/Cannabis (THC-COOH)||LOQ (ng/mL)||Detection Time* up to|
|Single Use||3||3 days|
|Moderate Use (4 times per week)||5 days|
|Heavy Use (daily)||10 days|
|Chronic Heavy Use||30 days|