Metabolite

A substance that is produced in the body due to the breakdown of another substance; can be active (can cause impairment) or inactive (does not cause impairment), i.e., THC breaks down to hydroxy-THC (active) then carboxy-THC (inactive). Detection of THC or hydroxyl-THC indicates the presence of a possibly impairing substance whereas the presence of carboxy-THC does not and only indicates prior exposure to THC.