Your Blood Carries Endocannabinoids That Track Exercise, Stress, Sleep, and Inflammation

Endocannabinoids aren't just in the brain. They circulate in the bloodstream, and their levels shift in response to specific physiological states. This review mapped those patterns across multiple domains.

Energy balance was the most consistent finding: endocannabinoid signaling tracked with increased energy consumption and storage, supporting the system's role in appetite and metabolism. Physical exercise mobilized endocannabinoids — a finding that contributes to the "runner's high" hypothesis and may explain some of exercise's analgesic and mood-elevating effects.

2-AG, one of the two main endocannabinoids, followed a strong circadian rhythm that became dysregulated when sleep was disrupted. Circulating levels also shifted with inflammation, chronic pain, and stress. In PTSD specifically, endocannabinoid concentrations were altered in ways that suggested the system's stress-recovery function was impaired.

This review connects cannabis science to broader biology. The endocannabinoid system isn't just relevant when someone uses cannabis — it's active in exercise, sleep, eating, stress recovery, and pain processing every day. Understanding these baseline patterns helps explain why cannabis affects so many different things: it's acting on a system that already touches nearly every major physiological process.

The exercise connection is particularly interesting. If runner's high partly comes from endocannabinoids, then exercise and cannabis may be acting on overlapping pathways — which could matter for both addiction treatment and mental health.