Cortisol
The primary stress hormone, measured in the morning when it peaks.
What is it
Cortisol is produced by the adrenal glands following a circadian rhythm. Morning measurement captures the daily peak and is used to evaluate adrenal function.
Why it's measured
Cortisol has been studied in research on stress, sleep, metabolism, and adrenal function. Both elevations and deficiencies have clinical significance.
Reference range
Standard laboratory reference
6 – 18 (morning) μg/dL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with chronic stress, Cushing's syndrome, and certain medications in research literature.
Lower
Has been associated with adrenal insufficiency and warrants clinical evaluation.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Typically measured between 6–9 AM when levels naturally peak.
Related markers
Common questions
Cortisol is produced by the adrenal glands following a circadian rhythm. Morning measurement captures the daily peak and is used to evaluate adrenal function.
It's one of the markers used to build a fuller picture of your health. On its own it tells you very little, so it's most informative when reviewed alongside related markers.
It's measured from a standard blood draw at Quest or LabCorp. Cortisol (morning) is one of the markers included in the OPTML Apex Panel, where your results are read across systems and reviewed by a U.S.-licensed physician.
Reference ranges vary by laboratory, and a single value rarely tells the whole story. Review your result with a physician in the context of your other markers, symptoms, and history.
Cortisol (morning) is one signal among many. Answer a few quick questions and we’ll point you to the panel that fits.
Related symptoms
A symptom is a signal, not a diagnosis. These guides explain what the evidence shows and the blood markers, including this one, that help find the cause.
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Find the right panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.
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