Endocannabinoid System

The endocannabinoid system (ECS) is one of the most important physiological systems in the human body, discovered in the 1990s during research into how THC affects the brain. The ECS regulates an enormous range of functions: mood, anxiety, memory, sleep, appetite, pain perception, immune response, fertility, motor control, neuroprotection, and overall homeostasis (the body's balance-maintaining processes). The ECS has four major components: (1) CB1 receptors — concentrated in the brain (hippocampus, basal ganglia, cerebellum, hypothalamus) and central nervous system; activation produces psychoactive effects, modulates pain, regulates appetite, and influences mood; (2) CB2 receptors — concentrated in the immune system (spleen, thymus, immune cells), peripheral nervous system, and gastrointestinal tract; activation produces anti-inflammatory effects without intoxication; (3) Endogenous cannabinoids (endocannabinoids) — anandamide (the "bliss molecule," named after the Sanskrit word for joy) and 2-AG (2-arachidonoylglycerol); these are the body's natural signaling molecules that bind cannabinoid receptors as part of normal physiological regulation; (4) Metabolic enzymes — FAAH (fatty acid amide hydrolase) breaks down anandamide; MAGL (monoacylglycerol lipase) breaks down 2-AG; these enzymes regulate how long endocannabinoid signals persist. Phytocannabinoids from cannabis (THC, CBD, CBG, etc.) interact with this system: THC binds CB1 receptors directly, mimicking anandamide but with longer effect duration; CBD inhibits FAAH (extending the body's natural anandamide effects) and modulates receptor signaling indirectly; CBG binds both CB1 and CB2 with low affinity. The ECS is also affected by exercise (the "runner's high" is endocannabinoid-mediated, not endorphin-mediated as previously believed), diet (omega-3 fatty acids support ECS function), and stress (chronic stress depletes endocannabinoid signaling). The concept of "Clinical Endocannabinoid Deficiency" proposed by Dr. Ethan Russo suggests that conditions like migraine, fibromyalgia, and IBS may stem from underactive ECS signaling — explaining why these conditions respond to cannabinoid therapy.