What is the Endocannabinoid System?

What is the Endocannabinoid System?

Even if you’re a long-time cannabidiol (CBD) user, you may be a bit hazy on how hemp’s many plant cannabinoids work in the body. Today we’ll be going over one of the most important questions for understanding how CBD affects us: “what is the endocannabinoid system?”

The endocannabinoid system (or ECS) is an integral part of all animals’ nervous systems, and it is responsible for a wide variety of vital functions. It helps us remain happy, healthy, and working at our best. Importantly for CBD fans, it’s also what allows the body to interact with the hundreds of plant cannabinoids that are naturally produced by hemp.

Endocannabinoid System Basics

The ECS was discovered in the early 1990s by a team of researchers studying the effects of THC. They uncovered a surprising fact: plant cannabinoids such as CBD and THC aren’t the only cannabinoids found in nature.

In fact, the human body produces its very own cannabinoids, known as endocannabinoids or endogenous cannabinoids. These work within the ECS to send signals between different parts of the body.

What is the Endocannabinoid System’s Purpose?

Since its discovery, the endocannabinoid system has been the subject of intense study. While research has uncovered that all animals have an endocannabinoid system, the precise functions of the ECS are still poorly understood.

Research has shown, however, that the ECS has a role in regulating the following vital functions:

  • Appetite
  • Memory formation and retention
  • Sleep
  • Mood
  • Metabolism
  • Perception of pain
  • Inflammation and other immune system responses
  • Fine motor control
  • Cardiovascular health

Some research has also suggested that the ECS is responsible for other important functions, including muscle formation, liver function, and reproductive health. While more research is needed before we can completely understand it, the ECS is undeniably a key part of maintaining our bodily integrity.

How does the ECS work?

Even if you’ve never used CBD or another cannabis product, your body’s ECS is hard at work at this very moment. The ECS helps to keep you calm, healthy, and in a state of biological homeostasis — the delicate equilibrium that keeps the body functioning at its best.

The endocannabinoid system is composed of three essential parts: endocannabinoids, endocannabinoid receptors, and enzymes.

Briefly: the body produces endocannabinoids to send signals between cells in the body. These endocannabinoids then move to the targeted cells, where they signal a response from the cell’s endocannabinoid receptors. With the endocannabinoid’s purpose served, the body then uses enzymes to break-down the endocannabinoid and dissolve it back into the bloodstream.


The body naturally produces its own cannabinoids. This is an important function of both the central and peripheral nervous systems. There are currently two known types of endocannabinoids: anandamide and 2-arachidonoylglycerol.

These endocannabinoids are produced as needed by the body, and they are used to send messages in between cells.

One of the critical functions of endocannabinoids is to send signals “backward”, to calm or quiet over-active cells that may be needlessly sending out too many signals of their own. Endocannabinoids travel to the targeted cell, where they bind to specialized cannabinoid receptors.

Cannabinoid Receptors

Cannabinoid receptors are located on cells throughout the body and are mainly distributed in the nervous system. There are two known types of cannabinoid receptors, known as CB1 and CB2 receptors.

  • CB1 Receptors are primarily located in the central nervous system, and especially within the spinal cord and brain. CB1 receptors play a direct role in memory, cognition, emotion, motor control, appetite stimulation, and the perception of pain
  • CB2 Receptors are primarily located in the peripheral nervous system. They are especially prevalent in the gastrointestinal and immune systems. CB2 receptors regulate inflammation and other immune system responses.

These receptors allow cells to detect cannabinoids — both endocannabinoids and plant cannabinoids such as CBD. Once a cannabinoid has been detected, receptors react by spurring the cell into action. Depending on the type of cell and the specific cannabinoid detected, these responses can vary widely.

Broadly speaking, endocannabinoid receptors often have the effect of halting or otherwise reducing the activity of overactive cells that are sending problematic signals to other parts of the body. For more on the important role of CB1 and CB2 receptors, check out our in-depth article on The Science of Endocannabinoid Receptors.


Once a cannabinoid has served its purpose, the body eliminates it through the production of enzymes. This is important so that the cannabinoid neither triggers multiple cannabinoid receptors nor re-triggers the same receptor after the initial need has passed. If the cannabinoid were not broken down in this way, it could potentially limit the communication of cells or cause other negative side effects.

There are two known types of enzymes that work within the ECS:

  • Fatty acid amide hydrolase, which eliminates anandamide
  • Monoacylglycerol acid lipase, which eliminates 2-arachidonoylglycerol.

How do Plant Cannabinoids Work with the ECS?

The endocannabinoid system also allows the body to interact with the many cannabinoids found in hemp and marijuana, which are referred to as “plant cannabinoids” or “phytocannabinoids”. Different phytocannabinoids interact with the endocannabinoid system in different ways.

THC and the ECS

Tetrahydrocannabinol (THC) is one of the principal plant cannabinoids found in marijuana, and it is responsible for the infamous “weed high”.

THC works much like the body’s own endocannabinoids. That is, it functions by binding to CB1 and CB2 receptors. Research suggests that THC’s ability to bind to both types of cannabinoid receptors is one reason its effects are so potent.

This binding causes THC to have a wide variety of effects on the body. Some of these effects are pleasant and largely the reason recreational users enjoy high-THC strains of marijuana. It can cause feelings of euphoria, increased appetite, and help eliminate nausea.

However, THC can also have a series of adverse side effects, including paranoia and anxiety.

CBD and the ECS

Cannabidiol (CBD) is the other main plant cannabinoid and is principally found in hemp. Unlike THC, CBD does not get users high and causes few if any side effects.

Researchers are still unsure of precisely how CBD interacts with the ECS. Studies have shown, however, that CBD does not bind to CB1 and CB2 receptors in the same way as other cannabinoids.

There are several theories about how CBD works within the body. Some believe that CBD interacts with a third type of cannabinoid receptor that is as yet undiscovered. Others believe that it works by delaying the break-down of endocannabinoids, thereby allowing them to have an enhanced effect.

Regardless of the mechanism by which it functions, CBD has been shown to have a variety of therapeutic effects on both the body and the mind. These effects vary depending on the method of ingestion and the dosage of CBD taken.

The Future of Endocannabinoid Research

While we may be able to answer the question “what is the endocannabinoid system?”, there’s still much we don’t understand about the ECS. More and more clinical attention is being paid to this vital part of our nervous system each year. As the scope of research develops and new findings are made, this line of inquiry promises new and innovative treatments for a wide variety of conditions.

For instance, a 2016 study on the ECS suggested that endocannabinoid deficiency may be the root cause of several conditions, including irritable bowel syndrome, fibromyalgia, and migraines.

The endocannabinoid system is complicated and, unfortunately, still poorly understood. Further research into this complex but vitally important system is necessary, but each discovery moves us towards a happier, healthier, more pain-free world.

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