11-Nor-9-carboxy-THC
11-Nor-9-carboxy-Δ9-tetrahydrocannabinol (11-COOH-THC or THC-COOH), often referred to as 11-nor-9-carboxy-THC or THC-11-oic acid, is the main secondary metabolite of tetrahydrocannabinol (THC) which is formed in the body after cannabis is consumed. == Metabolism and detection == 11-COOH-THC is formed in the body by oxidation of the active metabolite 11-hydroxy-THC (11-OH-THC) by liver enzymes.