“Adrenal fatigue” — a careful answer

If a practitioner told you your adrenals are exhausted, you were almost certainly describing something real — persistent fatigue, waking unrefreshed, an afternoon crash, poor stress tolerance. Those symptoms deserve an explanation. Adrenal fatigue isn't it.

A systematic review screened 3,470 studies and examined the 58 that tested whether cortisol patterns track with fatigue. Results contradicted each other regardless of study quality, and the review found no substantiation for adrenal fatigue as a medical condition (Cadegiani & Kater 2016). The Endocrine Society's position is that the tests sold for it are not based on scientific fact. Where cortisol genuinely does run low, the problem is usually upstream in the brain rather than in tired glands.

The part we most want you to read. When researchers assayed twelve over-the-counter "adrenal support" supplements, all twelve contained thyroid hormone and most contained at least one steroid hormone, including a synthetic glucocorticoid — while frequently being sold as hormone-free. Undisclosed glucocorticoids can suppress your HPA axis and cause the dysfunction the product claims to fix, and undisclosed thyroid hormone is unsafe with thyroid disease or when trying to conceive. If you take one, tell your provider — and don't stop abruptly without advice.

What to ask for instead: ferritin (not just hemoglobin), a full thyroid panel including TPO antibodies, B12, vitamin D, sleep apnoea screening, celiac serology, and glucose. Genuine adrenal insufficiency is rare but serious to miss — it is diagnosed with a morning cortisol and an ACTH stimulation test, not a saliva curve.

And if your cycles changed too: the diagnosis worth investigating is often functional hypothalamic amenorrhea, covered in Basics. It has a real mechanism, a clinical guideline, and a treatment.