After ingesting THC, it is transferred to the liver, where it is either eliminated or metabolized. Enzymes known as CYP2C and CYP3A convert THC into 11-OH-THC, which is psychoactive, and then to 11-COOH-THC, which is not psychoactive. This process creates at least 80 different metabolites that can have their own effects on the body's endocannabinoid system. These metabolites are stored in body fat and are gradually eliminated from the body through feces and urine.
The Food and Drug Administration (FDA) classifies any cannabis-derived substance containing more than 0.3% THC as a Schedule I controlled substance, while products with less than 0.3% THC are classified as agricultural hemp products.Diluting the urine may reduce the percentage of THC found in it, but it will not completely eliminate its metabolites. Studies have shown that THC and CBD do not interact with CYP1A2 and CYP2C19 in the same way as other cannabinoids and THC metabolites. The process of metabolizing THC also differs depending on whether it is smoked or eaten, and how long it stays in the system varies for each method. It is difficult to interpret urinary THC concentrations due to variables such as dose, frequency of use, time of urine collection, rate of release of cannabinoids stored in adipose tissue, and hydration status.