The Human Endocannabinoid System

CBD and THC fit like a lock and key into existing human cell receptors.
These receptors are part of the endocannabinoid system which impact physiological processes affecting pain modulation, memory and appetite and also has anti-inflammatory effects and other immune system responses.

The endocannabinoid system comprises two types of receptors, CB1 and CB2, which serve distinct functions in human health and well-being.

Infographic showing how CBD and THC fit together in human cell receptors.
Infographic showing endogenous G-protein-coupled cannabinoid receptors CB1 and CB2 in the endocannabinoid system.

The Endocannabinoid system

The endocannabinoid system (ECS) is a neurotransmitter system within the body made up of endogenous G-protein-coupled cannabinoid receptors (CB1 and CB2) and plays an important part in the regulation of homeostasis within the body. The ECS is found in all vertebrates (and even some invertebrates) and is thought to have an impact on many physiological symptoms such as sleep, stress, pain, appetite, memory, digestion and anxiety.

The body produces its own cannabinoids, called endocannabinoids. It is also triggered by cannabinoids from the cannabis plant of which THC and CBD are the most well-known and most extensively researched. CB1 receptors are located in abundance in the central and peripheral nervous system as well as the gastrointestinal and urinary tracts. CB1 receptors are believed to impact pain, sleep, appetite and even memory. CB2 receptors are found mostly in the immune system (tonsils, spleen, lymph nodes) and are responsible for the anti-inflammatory nature of cannabis. There is a very low concentration of CB1 and CB2 receptors in the brainstem and therefore, in contrast to opioids, cardiorespiratory depression and death resulting from cannabinoid consumption is almost impossible.

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  • ElSohly M., ‘Chemical Constituents of Cannabis. Cannabis and Cannabinoids – Pharmacology’, Toxicology and Therapeutic Potential, 2002, pp: 27-36.
  • Aggarwal, SK., ‘Cannabinergic pain medicine: a concise clinical primer and survey of randomized controlled trial results’, Clinical Journal of Pain, vol. 29 (2) 2013, pp. 161-171.
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