What does the Free Cortisol Diurnal Pattern (Dried Urine) test measure?

Why is Free Cortisol Diurnal Pattern (Dried Urine) measured?

The diurnal free cortisol pattern is used in functional and integrative practice to characterise the shape of the daily cortisol curve — its waking value, slope, and nocturnal level — rather than a single point. It is interpreted to assess HPA-axis function and patterns attributed to chronic stress. It does not replace serum or salivary cortisol or dynamic testing (such as the dexamethasone suppression or ACTH stimulation tests) for diagnosing Cushing's syndrome or adrenal insufficiency.

Reference ranges

Standard reference

Method-specific dried-urine intervals reported per collection point (waking, morning, afternoon, night) # REVIEWER FLAG: Dried-urine free cortisol reference intervals are proprietary to the Precision Analytical method and are not interchangeable with serum, salivary, or standard 24-hour urine ranges — reviewer to confirm against the laboratory's current intervals.

Functional medicine optimal

Functional-medicine pattern interpretation rather than a single optimal value # REVIEWER FLAG: Pattern-based functional interpretation is not a mainstream diagnostic standard — reviewer to confirm framing and ensure diagnostic claims are appropriately bounded.

Units

ng/mg creatinine

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.