What is the ECS, and what does the endocannabinoid system do?

The endocannabinoid system (ECS) is a network of cannabinoid receptors and the body's own cannabinoids that helps keep things like mood, pain, appetite, sleep and immune response in balance, and it's also where cannabinoids from the cannabis plant act. That's why it comes up almost every time we talk about how weed works in the body.

Medicine only started to get to know this system in the early 1990s, which tells you there's still a lot left to study and learn before we get the most out of cannabis as medicine.

To understand the basic properties and functions of the endocannabinoid system, first we need to understand what a cannabinoid is.

Basically, cannabinoids are the active chemical compounds in cannabis, a genus that includes all the plants classified as Cannabis (that is, Cannabis indica, Cannabis sativa and Cannabis ruderalis; industrial hemp is simply cannabis bred to be low in THC).

Types of cannabinoids

Researchers have identified more than 500 compounds across cannabis species, over 100 of them cannabinoids, but the two that seem to matter most for the plant's effects on the human body are THC (tetrahydrocannabinol) and CBD (cannabidiol). Other natural cannabinoids found in weed include CBG, CBC, THCA and THCV, just to name a few.

These active cannabinoids are behind the deep, wide-reaching effects cannabis has on the body's endocannabinoid system, and behind the therapeutic properties that patients turn to for so many conditions.

One of the coolest things about all this is that, just like the cannabis plant, humans make their own cannabinoids, called endocannabinoids (the ones produced by cannabis plants are called phytocannabinoids).

There are probably more left to discover, but the two main endocannabinoids in the human body seem to be anandamide and 2-AG (2-arachidonoylglycerol). To keep it simple, you can think of these two molecules as the body's homemade counterparts to plant cannabinoids like THC. Some studies suggest that endocannabinoid systems exist in a huge range of living things, from mammals and birds to fish and invertebrates.

Functionally, endocannabinoids work by binding to their matching receptors, called cannabinoid receptors. The most important ones are CB1 and CB2: CB1 mainly affects brain activity, while CB2 mainly affects the immune system and its interactions with the body's tissues and organ systems.

Since endocannabinoids are present in almost every type of cell and tissue in the human body, they (and their receptors) clearly have a lot of influence over many aspects of body and mind, which opens up plenty of possibilities for cannabis-based health research.

In fact, the endocannabinoid system (the full network of cannabinoids and receptors in the body) is so widespread that some researchers have described it as a bridge between body and mind, and possibly one of the most important physiological systems for maintaining human health.

Where are endocannabinoids found in the body?

Endocannabinoids have been found in abundance throughout the brain, organs, connective tissue, glands and immune cells. Studies have documented their role in regulating things like cell-to-cell communication, neurogenesis (the birth of new cells) and even apoptosis, the programmed "cell suicide" that clears out malignant cancer cells and other cells that are no longer useful.

So what happens when the body is low on endocannabinoids, or the ECS isn't working right? Some researchers think it could contribute to a range of health problems, a theory sometimes called clinical endocannabinoid deficiency, and that's one reason cannabis is thought to help with such a long list of medical conditions.

If endocannabinoids like 2-AG and anandamide help maintain health and balance (homeostasis) at the cellular level, it makes sense that cannabis, whose THC and CBD also interact with this system, could help when the ECS isn't firing on all cylinders. It's not a miracle cure, but it's a promising line of research.

You could say the body has its own built-in cannabis system, able to influence both mental and physical functions and to support overall balance. For conditions ranging from insomnia and anxiety to pain, inflammation or diabetes, cannabis may offer some relief, which makes it worth a conversation with your doctor.