What is the Endocannabinoid System?

A full and comprehensive guide to the ECS including how CBD and THC communicate and cause a change in the body.
A complex cell-signalling system that is just as important to life as the ability to respire or to digest food, the endocannabinoid system has real-life effects whether you consume cannabis or not. In the article, we aim to break down the functions of the ECS in an easy-to-digest manner to give a deeper level of understanding about what the endocannabinoid system (ECS) does.

The Endocannabinoid System – What is it and how does it work?

The endocannabinoid system, or ECS, is a complex communication system for the cells in all mammals, birds, reptiles and fish and it has roles in regulating sleep, mood, appetite, memory and reproduction. Playing an important role in the evolution of all vertebrate life on the planet, the endocannabinoid system is a network of molecules, receptors and enzymes that affect that has a significant role to play in your health and wellbeing.

How does the endocannabinoid system (ECS) work?

Present predominantly in the central nervous system (CNS) of the human body in the brain and spinal cord, but also having roles throughout almost all of the body, the ECS is constructed of 3 main aspects – endocannabinoid molecules, endocannabinoid receptors and metabolic enzymes.

Endocannabinoid molecules

Cannabinoid molecules that exist within your body naturally are called endogenous cannabinoids, often shortened to endocannabinoids. They are similar to the cannabinoids found in the cannabis plant, but they are produced naturally by your body whether you have consumed cannabis or not.

The two main endocannabinoid molecules that have been identified by scientists are anandamide and 2-arachidonoylglycerol (2-AG), both of which are neurotransmitters that interact with endocannabinoid receptors to cause a physiological effect.

Endocannabinoid receptors

Receptors for ECS are located throughout the human body but predominantly within the nervous system. The two main types of endocannabinoid receptor are CB1 and CB2, both of which play different functions:-

CB1 Receptors – Found in the central nervous system mostly in the brain and spinal cord and are mostly associated with cerebral effects such as behaviour, memory, cognition, motor control, appetite and pain.
CB2 Receptors – Located in the peripheral nervous system and effects are associated with the immune system and inflammation response.

The endocannabinoid molecules will bind the receptors which results in certain physiological effects depending on which molecule binds to which receptor.

the endocannabinoid system

Metabolic enzymes

The responsibility of metabolic enzymes in the ECS is to break down molecules once they have carried out their function into molecules that can easily be excreted out of the body.

The ECS and homeostasis

Research into the ECS is still in its infancy, and due to its complex nature and it is incredibly hard to monitor, the exact biological pathways by which cannabinoids cause their physiological effect isn’t fully understood. However, scientists believe that the endocannabinoid system’s predominant function is to maintain homeostasis within the body.

Homeostasis is defined as the tendency for a system to self-regulate to maintain an equilibrium which results in a stable physiological effect. For example, when something within the body operates outside of the stable range, the body will respond accordingly to correct this change to bring it back to the correct level.

Endocannabinoid molecules are believed to be created in response to a change in the body, such as the body temperature being too high. The idea is that the ECS will create a molecule, which will bind to a certain receptor that will result in the body temperature being brought back down to the correct level. Once the effect has been caused, the enzymes will break down the endocannabinoid molecules for excretion.

What are the functions of the ECS?

The ECS is located throughout the whole body and is responsible for a whole variety of different physiological functions. Research has linked the ECS with a wide range of functions, but most commonly it is linked with: –

  • The immune system and autoimmune disease
  • Chronic pain conditions
  • Inflammation
  • Neurological and neurodegenerative disease

The Immune System

Lots of chronic illnesses are caused through issues with the immune system, such as Multiple sclerosis (MS), Crohn’s disease and type 1 diabetes. These autoimmune diseases result from a signalling issue wherein the immune response is triggered because some cells of the body are seen as foreign invaders. The lack of recognition triggers the immune system to attack them in response. Certain cannabinoids work as an immune suppressor, lower the immune response and therefore the severity of an autoimmune disease.

peripheral nervous

Chronic Pain Conditions

Cannabinoids have been hailed as a non-opioid solution to chronic pain issues that come with negligible addictive properties in comparison. The most common medical use for cannabinoids in the US is for chronic pain conditions and contacts sports stars from the NFL, UFC and rugby have come out in favour of buying and using cannabinoids in sports.


Issues with the immune system and chronic pain are both very closely linked to inflammation, but there are also a whole host of other inflammatory conditions that do not fall under those brackets that cannabinoids have a role in helping. Research into cannabinoids has shown that they are able to effectively manage inflammation as good as, if not better than, common anti-inflammatory drugs such as ibuprofen.

Neurological and neurodegenerative disease

Cannabinoids are able to pass the blood-brain barrier and the brain is full of cannabinoid receptors, so cannabinoids are therefore able to exert a neurological effect. While some cannabinoids have been linked with the worsening of neurological disorders, especially when consumed from a young age, others have been shown to be an effective treatment in a range of neurological and neurodegenerative disorders from anxiety to Parkinson’s disease.

THC with the endocannabinoid

Tetrahydrocannabinol (THC) is the most studied and understood cannabinoid found within the cannabis plant and is predominantly known for its intoxicating properties. In other words, it gets you “high.”

When ingested, THC can bind to both CB1 and CB2 receptors where it exerts its effects on both the body and the mind. THC may reduce pain, stimulate your appetite, get you high and give your body a numb tingling feeling and whilst THC is known for its intoxicating properties, it also has a whole host of medical conditions for which it is used for relief.

CBD with the ECS

Cannabidiol (CBD) is the sister molecule to THC and has similar effects, but because it does not directly bind to the CB1 receptors as THC does, it does not have any intoxicating effects. In fact, CBD does not appear to directly bind to either of the main cannabinoid receptors, but instead it changes the way other cannabinoids bind, including the endocannabinoids previously mentioned.

Medical research into CBD is still in its infancy, but the initial findings and anecdotal evidence suggest that CBD could help with a whole variety of conditions which has propelled the CBD industry into a multi-billion dollar industry over recent years.

CB1 receptor and cb2 receptor

Endocannabinoid deficiency

The more research that is conducted into the way cannabinoids (and endocannabinoids) affect different people in a variety of ways, particularly medically, has resulted in a stronger association of cannabinoids and our health.

Theories have begun to emerge linking autoimmune, inflammatory and neurological conditions to a deficiency in some endocannabinoids, known as clinical endocannabinoid levels deficiency (CECD). Conditions such as IBS and fibromyalgia are believed to be affected.

Key Conclusions

The endocannabinoid system (ECS) has an extremely important biological role in humans and in all life. It plays a huge part in keeping the processes of the body stable, and any imbalance in the levels of endocannabinoids can result in conditions in which consumption of cannabinoids may be a long-term treatment option.

Experts are continuing to develop their understanding of the ECS, and as a result, we are seeing more condition being linked to treatments through the use of some part of the cannabis plant.