The cannabinoids

Over 500 chemical compounds are produced by the cannabis plant. Of these, at least 100 are unique to the cannabis plant —- the cannabinoids. The plant-derived cannabinoids are termed phytocannabinoids. The major phytocannabinoids, and those we know most about, are delta-9—tetrahydrocannabinol (THC) and cannabidiol (CBD). THC possesses psychoactive effects, while CBD is non-psychoactive (i.e. it does not alter perception or consciousness). 

The cannabinoids are biologically active chemicals. The concentration of cannabinoids varies throughout the plant (excluding seeds and roots). The highest concentration is found in the unfertilized female flower. 

The biological activity is mainly linked to the major cannabinoids THC and CBD. Although THC and CBD have unique activities, it is becoming clear that a wider range of cannabinoids and other constituents of the cannabis plant may be involved in its various therapeutic effects. These include the cannabinoids tetrahydrocannabivarin (THCV), cannabichromene (CBC), and cannabigerol (CBG). These minor cannabinoids are thought to subtly modulate or enhance biological effects when taken therapeutically. This effect may be the result of them working on their own, or working together with THC and CBD.