Cannabidiol, also known as CBD, is a non-psychedelic cannabinoid found in the hemp plant Cannabis sativa. It is a major constituent of the plant, representing up to 40% in its extracts.

CBD alone is not intoxicating, but it appears to affect the euphoric effect of THC (which is an isomer of cannabidiol) and add a sedative quality. Some research, however, indicates that CBD can increase alertness.
It may decrease the rate of THC clearance from the body, perhaps by interfering with the metabolism of THC in the liver. CBD does not appear to affect either the CB1 or CB2 receptors, possibly pointing to a still-undiscovered cannabinoid receptor in the body. It is perceived to have more effect on the body than does THC.

Medically, it appears to relieve convulsion, inflammation, anxiety, and nausea, as well as inhibit cancer cell growth. Recent studies have shown cannabidiol to be as effective as atypical antipsychotics in treating schizophrenia.