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A Simple Guide to the Endocannabinoid System

● How it works
● Functions of the ECS
● Endocannabinoid deficiency
● Summary

The endocannabinoid system (ECS) functions as a sophisticated intra-cell signalling matrix. Researchers first discovered it in the early 1990s while investigating THC, a dominant cannabinoid within the cannabis plant.Scientists do not yet completely understand all aspects of the ECS. But they have established that it influences the regulation of various functions and processes; these include:

● appetite
● sleep
● memory
● mood
● reproduction and fertility
The ECS is naturally active within the body and is not dependent on cannabis use.
Let’s examine how the ECS functions and interacts with cannabis.

How it works

The ECS consists of three key elements: endocannabinoids, enzymes, and receptors.


These are also referred to as endogenous cannabinoids. They are a type of molecule produced naturally in the body and are similar to cannabinoids.
Scientists have identified two core endocannabinoids:

● anandamide (AEA)
● 2-arachidonoylglyerol (2-AG)

These two endocannabinoids help regulate the internal functions of the body. The body produces them on demand; therefore, it is hard to establish what typical levels are for each.


These function to deconstruct endocannabinoids after they have performed their purpose. Two such enzymes have been identified:

● fatty acid amide hydrolase (deconstructs AEA)
● monoacylglycerol acid lipase (deconstructs 2-AG)

Endocannabinoid receptors

These receptors are located throughout the body. Endocannabinoids bind to the receptors as a signal when the ECS must take action.
The two dominant endocannabinoid receptors are:

● CB1 receptors (found mainly in the central nervous system)
● CB2 receptors (found especially in immune cells, in the peripheral nervous system)

Endocannabinoids can bind to either CB1 or CB2 receptors. The result of the binding process depends on the specific receptor’s location and type (CB1 or CB2).
For instance, endocannabinoids may bind to CB1 receptors located in a spinal nerve in order to alleviate pain. Alternatively, receptors may bind to CB2 receptors in immune cells in order to signal that the body is suffering from inflammation, which is a common indication of autoimmune disorders.

Functions of the ECS

The ECS is complex, and scientists have not yet mapped all of its functions, nor established exactly how it works. Through research, the ECS has been linked to the specific processes below:

● appetite and digestion
● bone remodelling and growth
● cardiovascular system function
● chronic pain
● inflammation and other immune system responses
● learning and memory
● liver function
● metabolism
● mood
● motor control
● muscle formation
● reproductive system function
● skin and nerve function
● sleep
● stress

All these functions contribute to homeostasis; the state of balancing the body’s internal environment. The ECS becomes activated when an external cause (e.g., fever or pain from an injury) introduces an imbalance in the body’s homeostasis. The ECS functions to help the body regain its ideal state.
Currently, scientists believe that the main purpose of the ECS is to maintain homeostasis within the body.

How does the ECS react to THC?

One of the dominant cannabinoids found in the cannabis plant is Tetrahydrocannabinol (THC). It is better known as the compound that produces the infamous ‘high’ feeling when cannabis is consumed. IN the body, THC behaves similarly to endocannabinoids, binding to both CB1 and CB2 receptors in the ECS.
This interaction process produces various effects on the body and mind. In some cases, THC may aid in alleviating pain or stimulate the appetite. However, in some cases, THC may also lead to feelings of anxiety and paranoia.
Current research is focusing on producing synthetic THC cannabinoids able to trigger only beneficial responses from the ECS.

How does the ECS respond to CBD?

Cannabidiol (CBD) is another dominant cannabinoid found in cannabis. But CBD does not produce the ‘high’ sensation associated with THC. Also, any side effects associated with CBD are rare and minimal, unlike those produced by THC.
Scientists are unclear about exactly how CBD impacts the ECS. However, what is clear is that CBD does not bind to CB1 or CB2 receptors in the same way as THC.
Many researchers believe that CBD prevents the deconstruction of endocannabinoids, thus allowing the endocannabinoids to have a greater effect on the body. Some experts believe that CBD may bind to receptors that have, as yet, not been identified.
Despite the lack of clarity regarding how CBD works exactly, studies indicate that CBD may help alleviate pain, nausea, and other symptoms common in several health conditions.

Endocannabinoid deficiency

Clinical endocannabinoid deficiency (CECD) is a theory supported by some experts. It suggests that when endocannabinoid levels are low in the body or the ECS is dysfunctional, it may contribute to certain conditions developing.
A review in 2016 covering more than 10 years of related research suggests that the theory may explain why certain people are prone to develop conditions such as migraine, fibromyalgia, and irritable bowel syndrome.
In each of the conditions mentioned above, there is no clearly identifiable underlying cause. Such conditions are often resistant to conventional treatments and, in some cases, may develop simultaneously.The working theory is that if CECD is an influencing factor in these conditions, then focusing on endocannabinoid production or the ECS may lead to effective treatment. But further investigation is still required.


A crucial function of the ECS is to maintain the body’s internal functioning stable, even if many of its other functions are still unclear. Scientists are gradually developing their understanding of how the ECS works, which may eventually lead to developing more effective treatments for certain health conditions.

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