The endocannabinoid system (ECS) performs thousands of vital functions in the human body, and yet it was only discovered in the 20th century.
The ECS is a set of proteins and fatty acid-based molecules that work together to control and regulate a vast range of metabolic functions. It relies on a set of proteins known as cannabinoid receptors, two of which—the CB1 and the CB2 receptors—happen to respond to the phytocannabinoids that are present in marijuana.
But, not knowing about the ECS didn’t stop us from using marijuana medicinally. Doing so came well before its recreational use.
The therapeutic use of cannabinoids was recorded in a classic medicine book by the Chinese emperor Shen Nung in 2737 BC, but that was before we even knew what a cannabinoid was or that our bodies have a whole system in our bodies based on them. The discovery of the first cannabinoid receptors in the 1980s helped to resolve the question of why and how we react to substances that are filled with cannabinoids; marijuana and hemp being the two most prime examples.
As we understand them now, cannabinoids are a diverse class of chemical compounds that interact with the cannabinoid receptors in cells that alter neurotransmitter release in the brain. These receptors are common in humans and other mammals, birds, fish, and even reptiles.
Endocannabinoids are produced naturally in the bodies of humans and other animals; phytocannabinoids are created by plants, like marijuana and hemp; synthetic cannabinoids can be artificially produced and are typically done so for research reasons.