What is the Endocannabinoid System?

The circulatory, respiratory, and nervous systems have all been known about, or at least accurately described by scientists, for hundreds of years. With that in mind, it’s kind of shocking that many adults have to ask, “What is the endocannabinoid system?”

Shocking, but not unexpected.

That is because until about 30 years ago we had no idea that the endocannabinoid system (ECS) existed. It was found on accident by some researchers who were exploring the medical benefits of THC, a cannabinoid found in cannabis.

In fact, this is how the system got its name. Endo meaning internal, or within, and cannabinoid, which the classification that the compound THC falls under.

Unlike most of the biological systems of the body, scientist know relatively little about the ECS. We do know however, the ECS is responsible for regulating many normal bodily functions, chemical levels, and processes.

What are the
Endocannabinoid System’s Functions?

While we are still learning the workings of the endocannabinoid system, we know that it helps to maintain homeostasis in bodily functions throughout the body.

Think of Goldilocks and the Three Bears. In this fairy tale Goldilocks tries on porridge that is too hot, a second that is too cold, before trying the third that is “just right”.

The endocannabinoid system works with the chemicals in your body to maintain conditions that allow the body to function normally. It is working towards maintaining “just right”.

When the ECS is not able to keep homeostasis, the result is the development of disease and medical conditions.

How does the Endocannabinoid System Work?

So we know what the endocannabinoid system does, but how does it help maintain homeostasis? There are three important components to this system. The three things are endocannabinoids, cannabinoid receptors, and enzymes

Cannabinoid Receptors

Cannabinoid receptors are found throughout the body and come in at least two forms, CB1 and CB2. CB1 receptors are abundant in the brain and nervous system. CB2 receptors are more abundant in the rest of the body.

There is starting to become evidence that these G protein-coupled receptors are more diverse than these two, but nothing is definitive yet.

These receptors sit on and around different cells and monitor conditions. When they find something that is not “just right” they signal the body to start producing endocannabinoids.


Endocannabinoids are naturally occurring molecules in the body that bind and stimulate the cannabinoid receptors that are part of the ECS.

So far, two main endocannabinoids have been identified: anandamide and 2-AG. Both are fat based molecules, and they are made as they are needed, they aren’t found floating around the body at random.

Early research points at anandamide having a large impact on working memory and early stage development, while 2-AG is found in significant quantities in the central nervous system.

Anandamide seems to also interact more with the CB1 receptors, while 2-AG is more active with CB2 receptors.

Metabolic Enzymes

The last piece of the endocannabinoid system is metabolic enzymes. These enzymes regulate how long different endocannabinoids are used.

Not only do these enzymes fuel and promote endocannabinoid function when they are needed, but they destroy the endocannabinoids once they are no longer needed.

Most hormones and neurotransmitters are stored in the body after use, this is a major difference between them and endocannabinoids. The enzymes are important though because you would not want the balance to upset the opposite way it was when they were produced.

How Do THC and CBD interact with the ECS?

THC and CBD are known as phytocannabinoids… cannabinoids that occur in plants. We cover this in depth in our “What is CBD” guide. Just like endocannabinoids, these compounds effect the CB1 and CB2 receptors throughout the body.

We do know that THC and CBD react differently with the receptors in your body than our normal endocannabinoids do.

THC, for instance, activates the CB1 receptor in your brain, causing the “high” effect associated with cannabis. The enzymes that break down anandamide when it is activating the CB1 receptors don’t work on cannabis, which explains the long duration of a THC high.

CBD differs from THC in that instead of activating the CB1 receptor, it seems to increase levels of endocannabinoids throughout the brain. This might explain CBD’s early success as an anti-anxiety treatment.