Last updated: October 2026
The endocannabinoid system (ECS) is a signalling network in the body made of cannabinoid receptors, the body’s own cannabinoids, and the enzymes that make and break them down. It helps regulate processes such as mood, appetite, pain, sleep, memory and immune function. It was discovered in the late 1980s and 1990s while scientists were studying how cannabis works.
Below: the three parts of the ECS, what it does, how THC and CBD interact with it, the “endocannabinoid deficiency” theory, and what’s still unknown.
The three parts of the endocannabinoid system
| Part | What it is | Examples |
|---|---|---|
| Receptors | Proteins on cells that receive cannabinoid signals | CB1, mostly in the brain and nerves; CB2, mostly in immune cells |
| Endocannabinoids | Cannabinoid-like molecules the body makes on demand | Anandamide and 2-AG |
| Enzymes | Build endocannabinoids, then break them down once they’ve done their job | FAAH breaks down anandamide; MAGL breaks down 2-AG |
How it was discovered
| Year | Discovery |
|---|---|
| 1964 | THC identified as the main intoxicating part of cannabis |
| 1988 to 1990 | The CB1 receptor found and its gene cloned |
| 1992 | Anandamide, the first endocannabinoid, identified |
| 1993 | The CB2 receptor identified |
| 1995 | 2-AG identified |
What does the endocannabinoid system do?
The ECS works mainly as a feedback system: endocannabinoids are released when needed and act locally to dial other signals up or down, then are quickly broken down. Research links it with:
- mood and the stress response
- appetite and metabolism
- pain signalling
- sleep and memory
- immune function and inflammation
- reproduction and development
Much of this comes from animal and lab research. How it all works in people is still being studied.
How THC and CBD interact with it
| THC | CBD | |
|---|---|---|
| CB1 receptors | Activates them strongly; this causes the “high” | Binds only weakly; doesn’t cause a high |
| Other targets | Fewer | Acts on several non-cannabinoid targets, including serotonin (5-HT1A) and TRPV1 receptors, in lab studies |
| Endocannabinoid levels | Not directly | May slow the breakdown of anandamide in lab studies; unclear at supplement doses |
So the common claim that CBD “works on your ECS” is a simplification: CBD’s effects come from many targets, and most evidence is from the lab. See CBD vs THC and does CBD get you high?
Is there such a thing as endocannabinoid deficiency?
“Clinical endocannabinoid deficiency” is a theory, proposed by researcher Ethan Russo, that some conditions such as migraine, fibromyalgia and IBS may involve low endocannabinoid activity. It’s an interesting idea, but it isn’t an accepted diagnosis, there’s no test for it, and it hasn’t been proven. Be wary of any product claiming to “fix” an ECS deficiency.
Can you “support” your endocannabinoid system?
There’s no proven way to “boost” the ECS with supplements. Research hints that exercise, sleep and stress management influence endocannabinoid levels, which are good habits anyway. Some people use CBD as part of a routine, but claims that it “balances” the ECS go beyond the evidence.
The FSA’s 10mg a day figure is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication. We don’t recommend our products during pregnancy or breastfeeding.
FAQs
What is the endocannabinoid system in simple terms?
A signalling network of receptors, the body’s own cannabinoid-like molecules and enzymes, which helps regulate mood, appetite, pain, sleep and immunity.
Does the body make its own cannabinoids?
Yes. The main ones are anandamide and 2-AG, made on demand and broken down quickly.
How does CBD affect the endocannabinoid system?
Only weakly at cannabinoid receptors. CBD acts on several other targets and may slow anandamide breakdown in lab studies.
What is endocannabinoid deficiency?
An unproven theory that some conditions involve low endocannabinoid activity. It isn’t a recognised diagnosis.
Where are CB1 and CB2 receptors found?
CB1 mainly in the brain and nervous system; CB2 mainly in immune cells.
Sources
- Lu HC, Mackie K. An introduction to the endogenous cannabinoid system. Biol Psychiatry, 2016.
- Matsuda LA et al. Structure of a cannabinoid receptor and functional expression of the cloned cDNA. Nature, 1990.
- Devane WA et al. Isolation and structure of a brain constituent that binds to the cannabinoid receptor. Science, 1992.
- Munro S et al. Molecular characterization of a peripheral receptor for cannabinoids. Nature, 1993.
- Russo EB. Clinical endocannabinoid deficiency reconsidered. Cannabis Cannabinoid Res, 2016.
