There are at least two types of cannabinoid receptors. Many of the effects of cannabinoids and endocannabinoids are mediated by two G protein-coupled receptors (GPCRs), CB1 and CB2, although there is new evidence that additional receptors may be involved.
CB1 receptors are primarily found in several brain regions and the central nervous system. They are also found in the cerebellum and in both male and female reproductive systems. These receptors mediate many of the psychoactive effects of cannabinoids. CB2 receptors are predominantly distributed in the immune system. They appear to be responsible for anti-inflammatory and other immune-related activity.
The two primary endocannabinoids produced by the human body interact directly with these receptors.