There is much more to the cannabis plant besides THC. There are over 110 different cannabinoids, like THCA, CBN and CBG, within the cannabis plant, but two are pertinent to cancer patients. Non-psychoactive CBD is what many medical cannabis patients are looking for, and is used to treat everything from muscle pain to epilepsy. But in order to reap the full benefits from CBD, some THC must be present. Read more here.