The endogenous cannabinoid system, named after the plant that led to its discovery, is perhaps the most important physiologic system involved in establishing and maintaining human health.

Endocannabinoids and their receptors are found throughout the body: in the brain, organs, connective tissues, glands, and immune cells. In each tissue, the cannabinoid system performs different tasks, but the goal is always the same: homeostasis, the maintenance of a stable internal environment despite fluctuations in the external environment.
Experts are still trying to fully understand the ECS. But so far, we know it plays role in regulating a range of functions and processes, including:

• sleep

• mood

• appetite

• memory

• reproduction and fertility

The ECS exists and is active in your body even if you don’t use cannabis.

How does it work?

The ECS involves three core components: endocannabinoids, receptors, and enzymes.

Endocannabinoids

Endocannabinoids, also called endogenous cannabinoids, are molecules made by your body. They’re similar to cannabinoids, but they’re produced by your body. The term “endo” refers to “within,” as in within the body.

Experts have identified two key endocannabinoids so far:

• anandamide (AEA) 2-arachidonoylglyerol (2-AG) These help keep internal functions running smoothly. Your body produces them as needed, making it difficult to know what typical levels are for each.

Endocannabinoid receptors

These receptors are found throughout your body. Endocannabinoids bind to them in order to signal that the ECS needs to take action.

There are two main endocannabinoid receptors:

• CB1 receptors, which are mostly found in the central nervous system

• CB2 receptors, which are mostly found in your peripheral nervous system, especially immune cells

Different Endocannabinoids can bind to either receptor. The effects that result depend on where the receptor is located and which endocannabinoid it binds to.

For example, endocannabinoids might target CB1 receptors in a spinal nerve to relieve pain. Others might bind to a CB2 receptor in your immune cells to signal that your body’s experiencing inflammation, a common sign of autoimmune disorders.

Enzymes

Enzymes are responsible for breaking down endocannabinoids once they’ve carried out their function.

There are two main enzymes responsible for this:

• fatty acid amide hydrolase, which breaks down AEA

• monoacylglycerol acid lipase, which typically breaks down 2-AG

Cannabinoids promote homeostasis at every level of biological life, from the sub-cellular, to the organism, and perhaps to the community and beyond. Here’s one example: autophagy, a process in which a cell sequesters part of its contents to be self-digested and recycled, is mediated by the cannabinoid system. While this process keeps normal cells alive, allowing them to maintain a balance between the synthesis, degradation, and subsequent recycling of cellular products, it has a deadly effect on malignant tumor cells, causing them to consume themselves in a programmed cellular suicide. The death of cancer cells, of course, promotes homeostasis and survival at the level of the entire organism.

The endocannabinoid system, with its complex actions in our immune system, nervous system, and all of the body’s organs, is literally a bridge between body and mind. By understanding this system we begin to see a mechanism that explains how states of consciousness can promote health or disease.

In addition to regulating our internal and cellular homeostasis, cannabinoids influence a person’s relationship with the external environment. Socially, the administration of cannabinoids clearly alters human behavior, often promoting sharing, humor, and creativity. By mediating neurogenesis, neuronal plasticity, and learning, cannabinoids may directly influence a person’s open-mindedness and ability to move beyond limiting patterns of thought and behavior from past situations. Reformatting these old patterns is an essential part of health in our quickly changing environment.

Research suggests that the ECS may be a potential therapeutic target in numerous physiological conditions such as:

• energy balance

• appetite stimulation

• blood pressure

• pain

• embryonic development

• nausea and vomiting control

• memory and learning

• immune response

In addition, it may be a target for pathological conditions such as:

• Parkinson’s disease

• Huntington’s disease

• Alzheimer’s disease

• Multiple sclerosis

How does the body produce and release endocannabinoids?

The human body naturally produces endocannabinoids. They are present in various organs and tissues, such as the muscle, brain, and circulating cells. Endocannabinoids become active when they bind with a cannabinoid receptor. The receptors are also located throughout the body.

Research continues on the exact physiological mechanism that promotes or triggers the binding of the receptors to the endocannabinoids. But experts theorize that when a system in the body is out of balance, the receptors bind to the cannabinoids to help correct the problem.

The endocannabinoid system is precise. For example, if body temperature is out of the normal range, the ECS regulates it without altering other processes. Once the ECS brings the body back into balance, the enzymes break down the cannabinoids to prevent overcorrecting the problem.

What is the function of endocannabinoids and the ECS?

The function of cannabinoids within the ECS is vast. In fact, researchers still do not fully understand the exact role of cannabinoids, although the ECS clearly plays a large part in how well the body functions.Research suggests that the ECS plays a key role in contributing to homeostasis. Homeostasis refers to the maintenance of stability, or optimal conditions, within the body to promote proper functioning. For example, the body maintains homeostasis for temperature, blood sugar, and appetite. Experts believe that if the body falls out of the normal range, the ECS helps the body to return to the optimal range and maintain homeostasis. Research suggests the ECS may help regulate the function of the following:

• appetite and digestion

• sleep

• Pain sensation

• inflammation and other immune responses

• mood

• metabolism

• learning and memory

• reproduction system function

• motor control

• cardiovascular system function

• muscle formation

• bone remodeling and growth

• liver function

• reproductive system function

• stress

• skin and nerve function

What are the therapeutic uses of cannabinoids?

Research indicates that the ECS may contain multiple promising therapeutic targets. While the body can produce endocannabinoids, there are also many cannabinoids present in the Cannabis plant which are of medical interest.

Two of the most well-known cannabinoids include tetrahydrocannabinol (THC) and cannabidiol (CBD). They can also bind to cannabinoid receptors and produce similar effects to endocannabinoids. THC is the cannabinoid that causes the “high” that people may associate with cannabis, whereas CBD does not produce this sensation.

How does THC interact with the ECS?

Tetrahydrocannabinol (THC) is one of the main cannabinoids found in cannabis. It’s the compound that gets you “high.”

Once in your body, THC interacts with your ECS by binding to receptors, just like endocannabinoids. It’s powerful partly because it can bind to both CB1 and CB2 receptors.

This allows it to have a range of effects on your body and mind, some more desirable than others. For example, THC may help to reduce pain and stimulate your appetite. But it can also cause paranoia and anxiety in some cases.

Experts are currently looking into ways to produce synthetic THC cannabinoids that interact with the ECS in only beneficial ways.

How does CBD interact with the ECS?

The other major cannabinoid found in cannabis is cannabidiol (CBD). Unlike THC, CBD doesn’t make you “high” and typically doesn’t cause any negative effects.

Experts aren’t completely sure how CBD interacts with the ECS. But they do know that it doesn’t bind to CB1 or CB2 receptors the way THC does.

Instead, many believe it works by preventing endocannabinoids from being broken down. This allows them to have more of an effect on your body. Others believe that CBD binds to a receptor that hasn’t been discovered yet.

While the details of how it works are still under debate, research suggests that CBD can help with pain, nausea, and other symptoms associated with multiple conditions.

Studies are ongoing to determine the therapeutic benefits of cannabinoids. For example, a 2016 study investigated the effect of CBD on joint inflammation in rats. The study suggests that applying a topical gel containing CBD decreased pain and joint swelling in rats without side effects.

What about endocannabinoid deficiency?

Some experts believe in a theory known as clinical endocannabinoid deficiency (CECD). This theory suggests that low endocannabinoid levels in your body or ECS dysfunction can contribute to the development of certain conditions.

A 2016 article reviewing over 10 years of research on the subject suggests the theory could explain why some people develop migraine, fibromyalgia, and irritable bowel syndrome.

None of these conditions have a clear underlying cause. They’re also often resistant to treatment and sometimes occur alongside each other.

If CECD does play any kind of role in these conditions, targeting the ECS or endocannabinoid production could be the missing key to treatment, but more research is needed.

Additional research indicates that cannabinoids may be helpful in treating a variety of conditions such as:

• pain in adults

• abnormal muscle tightness associated with multiple sclerosis

• nausea and vomiting associated with chemotherapy

• sleep disturbances

Research continues on how inhibiting or stimulating the endocannabinoid system could have medical and health benefits.

Summary

Not everything is known about the ECS, but research suggests that it plays a vital part in maintaining balance and proper function in the body.

The ECS consists of endocannabinoids, receptors, and enzymes, which work together to help maintain stability in processes such as temperature, sleep, and mood.

The ECS may contain many therapeutic targets, which researchers may be able to use to help treat various health conditions.