Cannabinoids are chemical compounds that activate cannabinoid receptors in the brains of animals. The presence of a cannabinoid receptor in rats has been discovered in 1988. Since then, scientists have proved the existence of such receptors in the cells of mammals, birds, fish and reptiles. Three types of cannabinoids are distinguished by scientists: endocannabinoids, phytocannabinoids and synthetic cannabinoids. I will discuss these three groups of cannabinoids briefly, and will then focus this article on phytocannabinoids and their effect on humans.


The cannabinoids that are produced by the bodies of animals are called endocannabinoids. These cannabinoids serve as so called “lipid messengers”, which are signaling molecules that are released by cells to activate cannabinoid receptors which exist on nearby cells. Because these lipid messengers cannot be stored in vesicles, they are often biosynthesized in the plants when and where they are needed.


The cannabinoids that are produced by plants are named phytocannabinoids. The most studied phytocannabinoids are the chemical compounds that are concentrated in the resin that is created in parts of the cannabis plant. The parts that produce the most concentrated resin are the glandular trichomes. The most studied phytocannabinoids are tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN). Cannabinoids are bio synthesized by several plant species known to men. The best known cannabinoids that are not derived from Cannabis are the alkylamides from the Echinacea species, which is a plant in the daisy family. The cannabinoids in this plant are found in the whole plant structure, but are most concentrated in the roots and flowers of the plant.

Synthetic cannabinoids

Cannabinoids that are created via laboratory synthesis can be divided into two groups: those that are based on known cannabinoid structures and those that are not. Traditionally, scientific research has focused on the examination and production of cannabinoids that are similar to those found in plants. More recently, scientists have focused on creating molecules that are different from both endocannabinoids and phytocannabinoids. These compounds have gained popularity both as research and as recreational substances due to the fact that they bypass the laws that prohibit the use of THC.