4HCannabiol acid

Description

The presence of tetrahydrocannabinol carboxylic acid (THC-COOH), a major metabolite of delta-9-tetrahydrocannabinol, in urine at concentrations >15.0 ng/mL is a strong indicator that the patient has used marijuana.
The metabolite of marijuana (THC-COOH) has a long half-life and can be detected in urine for more than 7 days after a single use. The presence of THC-COOH in urine >100.0 ng/mL indicates relatively recent use, probably within the past 7 days. Levels >500.0 ng/mL suggest reoccurring and recent use. Chronic use causes accumulation of THC and THC-COOH in adipose tissue such that it is excreted into the urine for as long as 30 to 60 days from the time chronic use is halted.