The endocannabinoid system (ECS) is a group of cannabinoid receptors located in the brain and throughout the central and peripheral nervous systems, consisting of neuromodulatory lipids and their receptors.
There are two main types of receptors in the ECS: CB1 and CB2. CB1 receptors are primarily located in the central nervous system and brains of mammals, and CB2 is generally found in the peripheral nervous system. Mammals produce two main endocannabinoids: 2-AG and anandamide.