7 evidence-graded facts. Click any card for the full summary and sources.
Humans produce endocannabinoids — anandamide (named from the Sanskrit "ananda", bliss) and 2-AG — which activate the same receptors as plant THC. The system was discovered because THC worked, not the other way around: researchers found the receptor first (1988), then asked why it existed.
The Endocannabinoid System STRONG EVIDENCECB1 receptors are expressed at densities rivaling glutamate and GABA receptors across the cortex, hippocampus, basal ganglia and cerebellum. Their density in movement and memory regions explains both the therapeutic reach of cannabinoids and their side-effect profile.
The Endocannabinoid System STRONG EVIDENCEThe ECS is a homeostatic signaling system: it tunes hunger, pain signaling, stress response, sleep and memory consolidation. It works "on demand" — synthesized when needed, broken down quickly by enzymes (FAAH, MAGL). This is why cannabis touches so many functions at once.
The Endocannabinoid System STRONG EVIDENCEWhile CB1 dominates the brain, CB2 receptors concentrate in immune cells and peripheral tissues, modulating inflammation. CB2 is the main reason researchers believe cannabinoids could have anti-inflammatory effects without a high.
The Endocannabinoid System MODERATE EVIDENCEPeople carry different versions of FAAH, the enzyme that breaks down anandamide. One common variant slows that breakdown, raising natural endocannabinoid levels — carriers show measurably different responses to THC, including lower dependence risk in several studies. Same joint, different brain.
The Endocannabinoid System MODERATE EVIDENCEFor decades the post-run euphoria was blamed on endorphins — but endorphins barely cross the blood-brain barrier. Animal and human studies point instead to anandamide surging after sustained exercise. Your ECS, the same system THC hijacks, is the body's own reward for endurance.
The Endocannabinoid System STRONG EVIDENCECB1 and CB2 receptors, plus the enzymes that make and destroy endocannabinoids, are expressed across the gastrointestinal tract, skin, liver, fat tissue and bone. The ECS is a whole-body regulatory network, which is why cannabinoid research now spans IBS, eczema, liver disease and osteoporosis.
The Endocannabinoid System