So what is a stoner or casual cannabis consumer, or medical patient, for that matter to do when all you need is a single, reliable option? If you have to pass a drug test for weed, it is important to understand how drug tests and detoxing works in order to put yourself in the best position to pass. The natural timeline for THC leaving your system is different for everyone, as it is dependent on a number of factors that include age, body mass, metabolism, frequency of exposure, duration of exposure, and the potency of the cannabis consumed. For most people, it can take as long as weeks for traces of THC from cannabis to naturally exit your system from the last point you consumed. Unlike other testable substances, THC is fat-soluble which means it gets stored in your fat cells and organs. Generally speaking, the less frequent you consume and less body fat you have the lesser amount of time it will take you to cleanse.