Nabiximols (Sativex), a multiple sclerosis drug made from a combination of TCH and CBD, is approved in the United Kingdom and Canada to treat MS pain. However, researchers think the CBD in the drug may be contributing more with its anti-inflammatory properties than by acting against the pain. Clinical trials of CBD are necessary to determine whether or not it should be used for pain management.

Along those same lines, most over-the-counter medications have side effects. At this point, the side effects from CBD have been very minimal and very minor. There have been some complaints of tiredness, upset stomach and a few cases of diarrhea. Outside of those few side effects most people have stated they have encountered minor side effects or none at all.

Most human studies of CBD have been done on people who have seizures, and the FDA recently approved the first CBD-based drug, Epidiolex, for rare forms of epilepsy. Clinical trials for other conditions are promising, but tiny. In one Brazilian study published in 2011 of people with generalized social anxiety disorder, for example, taking a 600-mg dose of CBD (higher than a typical dose from a tincture) lessened discomfort more than a placebo, but only a dozen people were given the pill.
If one takes high amounts of CBD, the cannabinoid can temporarily neutralize the activity of P450 enzymes and thus alter the way drugs are metabolized inside the body. This action of CBD can be regarded as a side effect, but it’s not always a negative trait, as the deactivation of P450 enzymes is one of the mechanisms through which CBD neutralizes THC as well.

A study highlighting this was performed approximately one decade ago. The study found a link between IBS sufferers and clinical endocannabinoid deficiency, which relates back to the fact that the system directly impacts intestinal motility and function. When CBD was used to activate and regulate the endocannabinoid system, sufferers of IBS saw significant symptom improvement. (42)