Cortisol: why the stress hormone isn't always bad

Doctors say cortisol is an essential hormone that normally fluctuates through the day and that true cortisol disorders are uncommon; they caution that single tests and unregulated supplements can be misleading.

Cortisol, often called the "stress hormone," has become a frequent topic in wellness conversations online. Influencers sometimes link common symptoms to chronically high cortisol and promote tests or supplements. Endocrinologists emphasize that cortisol is essential for many body functions, that levels change minute-to-minute and across the day, and that clear cortisol disorders are relatively rare. They also report concern about people ordering one-off tests or using unregulated products without medical oversight. Key points: - Cortisol is produced by the adrenal glands and influences inflammation, metabolism, blood pressure and immune function. - Levels normally peak after waking and fall at night, and they also rise during illness or acute stress. - Disorders primarily driven by cortisol are uncommon; chronic low cortisol is called adrenal insufficiency and chronic high cortisol is known as Cushing's syndrome. - Diagnoses typically require multiple tests and clinical context; a single blood test often does not provide a reliable picture. - Some factors, such as birth control pills, can alter test results and lead to misleading readings. - There are no proven over-the-counter treatments to reliably lower or raise cortisol, and unregulated supplements may pose risks. Summary: For most people, cortisol carries out essential daily roles and does not require targeted treatment. Doctors report that interpreting cortisol levels requires careful testing and clinical judgment, and they express caution about single tests and unproven supplements. Research into specific medical treatments for chronically high cortisol is ongoing.