Lay opinion vs evidence: Cortisol Alltag

In everyday life, cortisol is often labeled the 'stress hormone' and blamed for everything from weight gain to insomnia and burnout. The scientific evidence is more nuanced: cortisol follows a natural circadian rhythm (high in the morning, low at night), and short-term fluctuations are normal. Chronically elevated levels can occur with persistent stress or conditions like Cushing's syndrome, but single spot measurements from saliva or blood are rarely clinically meaningful due to many confounders (time of day, food intake, exercise). Many commercial tests overstate the relevance of isolated readings. Evidence for 'cortisol optimization' via supplements or specific diets is weak. Instead, established stress management strategies (sleep, exercise, mindfulness) have stronger support. Bottom line: cortisol is a useful biomarker but often overinterpreted in daily life.