Clinical review pending. This article has not yet been reviewed by a licensed clinician, and we would rather say so than print a name that does not exist.
What it is
Cortisol is a hormone produced by the adrenal glands. It follows a daily rhythm, typically peaking shortly after waking and falling across the day, and it is involved in blood glucose regulation, blood pressure, immune function and the response to stress.
It is essential. Framing it as a toxin to be eliminated, which is common online, is simply wrong.
Why the timing matters more than the number
Because cortisol follows a rhythm, a single measurement is close to meaningless without knowing when it was taken. A value that is entirely normal at eight in the morning would be unusual at ten at night. This is why properly conducted assessment specifies timing and often uses more than one sample.
About "adrenal fatigue"
You will encounter the term widely. It is not a recognized medical diagnosis, and systematic reviews have not found consistent evidence supporting it as an entity. That does not mean the symptoms people describe are imaginary. It means the label does not explain them, and using it tends to stop the search before the actual cause is found.
Genuine disorders of cortisol production do exist and are diagnosed with specific testing. They are also uncommon, and they are not diagnosed from a saliva kit bought online.
Lifestyle levers
- Sleep regularity. The rhythm above is anchored to your sleep and light exposure.
- Training load that matches recovery. Chronic overreaching is a stressor like any other.
- Alcohol and caffeine. Both interact with sleep, which anchors the rhythm.
- Actual recovery time. Unglamorous and effective.
Discuss with your clinician
If you have persistent, unexplained fatigue, unintended weight change, dizziness on standing or other significant symptoms, that deserves a proper evaluation rather than a direct to consumer hormone panel. The tests that matter here need correct timing and correct interpretation.
This is general education, not advice for you. It does not diagnose, treat or recommend anything for your situation. Talk with a licensed clinician about what applies to you, especially before changing anything if you have an existing condition or take medication.
References
- Cadegiani FA, Kater CE. "Adrenal fatigue does not exist: a systematic review." BMC Endocrine Disorders, 2016.
- Nieman LK et al. "The diagnosis of Cushing's syndrome: an Endocrine Society Clinical Practice Guideline." J Clin Endocrinol Metab, 2008.
These are public, peer reviewed sources about the underlying physiology. They are not studies of SiriusRX and they do not describe results anyone should expect from us.