Cortisol

Cortisol is the primary stress hormone, produced by the adrenal glands as the end-product of the HPA (hypothalamic-pituitary-adrenal) axis. It plays essential roles in glucose metabolism, blood pressure regulation, anti-inflammatory response, and the body's stress response.

Acute cortisol release: cortisol levels rise rapidly under perceived threat, returning to baseline once the threat passes. This is the system working correctly.

Chronic elevated cortisol: when stress is sustained without recovery, cortisol stays elevated. Chronic elevation drives many somatic symptoms: sleep disruption, immune dysfunction, digestion problems, weight gain (particularly visceral fat), mood symptoms, and accelerated aging markers.

Cortisol as biomarker: cortisol levels can be measured in saliva, blood, or urine, making it the most-cited biomarker of body-based therapy effects in research literature.

A representative study showed 24% cortisol reduction in the EFT group versus 14% in supportive-interview controls and 14% in no-treatment controls. The Baldwin 2017 Reiki RCT showed cortisol reduction in real-Reiki recipients above sham-Reiki controls. The mechanism is autonomic regulation through structured contact, slowed pace, and focused attention.

Why cortisol reduction matters clinically: because cortisol is downstream of the chronic sympathetic activation that drives many of the conditions body-based therapies address. Reducing cortisol does not just feel better; it shifts the substrate that produces the symptoms in the first place. Sleep improves, immune function recovers, GI symptoms ease, mood stabilises.

Cortisol is one of the more rigorous bridges between the body-based therapy effects and mainstream physiology. The mechanism is well-documented even where the explanatory metaphysics of specific modalities remains hypothesised.