My morning cortisol is low — what should I do?
Low morning cortisol prompts an ACTH-stimulation test to evaluate adrenal insufficiency. This is outside the optimization pathway and is referred for endocrine workup before further hormone strategy is set.
Full answer
An 8 a.m. cortisol meaningfully below the lower reference limit, especially with fatigue, dizziness, hyperpigmentation, salt craving, hyponatremia, or hyperkalemia, raises concern for adrenal insufficiency. The definitive evaluation is an ACTH-stimulation test, ideally with paired ACTH and aldosterone. This workup is outside the optimization pathway and is referred to endocrinology. Hormone optimization decisions are deferred until the adrenal axis is characterized because the entire HPA, thyroid, and gonadal axes inform each other.
Educational. Not a substitute for individualized provider review.
- Methodology — Primary source · oMeds
- Reviewed by Dr. Laura Purdy, MD, MBA · Clinical Director, oMeds · Last reviewed 2026-06-03