Cannabinoids are compounds that act on cannabinoid receptors CB1 and CB2.
The three major groups of cannabinoids are:
1) Endocannabinoids, which are produced endogenously in animals and include anandamide and 2-arachidonoylglycerol.
2) Phytocannabinoids, of which over 100 have been identified, are produced by Cannabis plants. These include both psychoactive (e.g. tetrahydrocannabinol (THC)) and non-psychoactive (e.g. cannabidiol) compounds.
3) Synthetic cannabinoids include classical cannabinoids (structural analogues of THC), cannabimimetics (including naphthoylindoles, phenylacetylindoles and benzoylindoles) and, compounds related to the endocannabinoids.