24-Hour Urine Cortisol vs DUTCH Test: Which to Use

Disclaimer: This article is for educational purposes only and does not constitute medical advice. Hormone testing and interpretation should always be conducted under the supervision of a qualified healthcare practitioner. Reference ranges cited are indicative and may vary by laboratory.

When a GP or endocrinologist orders a cortisol test, they almost always mean a morning serum draw or, for screening purposes, a 24-hour urine collection. When a functional medicine practitioner orders cortisol testing, they almost always mean the DUTCH, Dried Urine Test for Comprehensive Hormones. These two modalities share a starting point (urine cortisol) but are designed for fundamentally different clinical questions. Using one where the other is appropriate leads either to missed pathology or to clinically uninterpretable results.

This article explains what each test measures, where each performs best, what the DUTCH adds beyond a standard 24-hour collection, and how to navigate Australian ordering and cost considerations.

What the 24-Hour Urinary Free Cortisol Test Measures

The 24-hour urinary free cortisol (UFC) measures the cumulative excretion of unbound cortisol filtered through the kidneys over a complete collection day. Because free cortisol is the biologically active fraction not bound to cortisol-binding globulin (CBG), the UFC reflects integrated daily cortisol secretion with a degree of independence from CBG fluctuations that can confound serum total cortisol.

The collection captures roughly 1% of total daily cortisol production. Under normal physiology this fraction is tightly regulated, so an elevated UFC, particularly one exceeding three to four times the upper limit of normal, is strongly suggestive of true cortisol excess rather than artefact.

Why UFC Is the Standard Screen for Cushing's Syndrome

The Endocrine Society's clinical practice guideline on Cushing's syndrome recommends UFC as one of three first-line tests for diagnosis, alongside late-night salivary cortisol and the low-dose dexamethasone suppression test (Nieman et al., JCEM 2008). The guideline recommends that at least one of these tests returns an abnormal result before proceeding to confirmatory or localisation testing.

UFC performs well in this context because Cushing's syndrome is characterised by sustained cortisol hypersecretion across the day, which the 24-hour collection captures as a cumulative total. Sensitivity for Cushing's syndrome in most studies ranges from 79–98% depending on cut-off and assay; specificity is lower when mild or cyclic disease is present. A single normal UFC does not exclude Cushing's, guidelines recommend two to three collections to account for day-to-day variability and the episodic nature of cortisol secretion in some subtypes.

Limitations of the UFC

The 24-hour UFC is a blunt instrument outside of Cushing's screening:

• It provides a single integrated number, with no information about the diurnal cortisol rhythm, the cortisol awakening response, or afternoon/evening nadir.
• It does not measure cortisone, the inactive metabolite that reflects cortisol inactivation by 11β-HSD2 in the kidney.
• It does not capture cortisol metabolites such as tetrahydrocortisol (THF), allo-tetrahydrocortisol (allo-THF), and tetrahydrocortisone (THE), which together represent the bulk of cortisol clearance.
• Incomplete collection is a common source of error; a creatinine check is used to flag obvious under-collection but cannot correct for variable urine flow throughout the day.
• Results can be affected by high fluid intake and reduced renal function.

What the DUTCH Test Measures

The DUTCH panel collects four to five dried urine spots at timed intervals across the day (typically on waking, post-awakening (30–60 minutes later), afternoon, and before bed) with some versions extending to a second morning spot. The spots are dried on filter paper and sent to Precision Analytical's laboratory in the United States, where hormone metabolites are quantified by LC-MS/MS.

The DUTCH reports:

• Free cortisol at each time point, giving a diurnal curve
• Free cortisone at each time point
• Total cortisol metabolites (THF, allo-THF, THE) as a proxy for total cortisol production
• Cortisol awakening response (CAR) from the waking and post-awakening spots
• Sex hormone metabolites, oestrone, oestradiol, oestriol and their 2-OH, 4-OH, and 16-OH metabolites, progesterone metabolites, and androgens including DHEA, androsterone, and etiocholanolone
• Melatonin (some panels)
• Organic acids as nutritional markers on extended versions

Validation Evidence

A 2021 peer-reviewed study by Newman and Curran published in BMC Chemistry (PMC7962249) assessed the reliability of dried urine sampling for 25 hormones, organic acids, and melatonin metabolites. Intraclass correlation coefficients (ICCs) for reproductive hormone metabolites were above 0.90, indicating excellent test-retest reliability. A companion study (PMC7744704) confirmed that creatinine-corrected cortisol and cortisone values from four-spot dried urine show good agreement with 24-hour liquid urine collections for the same hormones when expressed per unit creatinine.

These studies establish methodological validity for the approach, though it is worth noting that the clinical interpretation of DUTCH patterns, particularly at the functional or subclinical level, has a more limited evidence base than the established diagnostic thresholds for 24-hour UFC in Cushing's screening.

Key Differences Between the Two Tests

Sensitivity and Specificity: A Practical Comparison

For Cushing's syndrome diagnosis, the 24-hour UFC is the clinically appropriate and guideline-recommended tool. The DUTCH test has not been validated for this purpose and should not be used as a screening or diagnostic instrument for cortisol excess pathology. An abnormal DUTCH free cortisol pattern warrants referral for formal endocrine evaluation using guideline-endorsed tests, the DUTCH result alone is not sufficient grounds for a clinical diagnosis.

For functional HPA axis assessment (the territory of burnout, subclinical HPA dysregulation, disrupted diurnal rhythm, inadequate cortisol awakening response, or relative cortisol insufficiency) the 24-hour UFC is largely uninformative. A total daily cortisol output within the normal range is consistent with markedly disturbed diurnal patterning, a blunted CAR, or impaired cortisol clearance. None of these are detectable from a single 24-hour number.

The cortisol awakening response and DUTCH test article on this site covers the CAR in detail: the 50–160% post-waking rise expected in healthy HPA function, what blunted versus exaggerated patterns indicate, and why the CAR is arguably the most information-dense single cortisol window available without a pharmacological challenge. That assessment is only possible with timed urine or saliva sampling, not with a 24-hour collection.

Similarly, the cortisol and DHEA-S adrenal panel explains why the cortisol-to-DHEA ratio requires accurate cortisol quantification at meaningful time points. The ratio derived from a 24-hour total versus a single morning serum DHEA-S is methodologically inconsistent; the DUTCH captures both markers on a comparable dried urine platform.

What DUTCH Adds: Cortisone and Metabolite Ratios

Two DUTCH outputs deserve particular attention because they have no equivalent in a standard 24-hour UFC.

Cortisone. Cortisone is the inactive form of cortisol produced by the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), primarily in the kidney. The ratio of free cortisol to free cortisone on the DUTCH reflects the relative activity of this enzyme: a high cortisol-to-cortisone ratio suggests reduced 11β-HSD2 activity, which can be relevant in conditions such as apparent mineralocorticoid excess, metabolic syndrome, and obesity. The 24-hour UFC cannot make this distinction.

Total cortisol metabolites. THF, allo-THF, and THE represent the majority of cortisol clearance through hepatic 5α- and 5β-reduction. Their sum correlates with overall cortisol production rate more closely than free cortisol excretion alone, some individuals clear cortisol rapidly (high metabolites, moderate free cortisol) while others have sluggish clearance (low metabolites, elevated free cortisol). This distinction matters for interpreting whether a slightly elevated free cortisol reflects genuine overproduction or simply reduced clearance. A 24-hour UFC cannot differentiate these scenarios.

Sex hormone metabolites. The oestrogen metabolite panel, specifically the 2-OH:16-OH ratio and the proportion of 4-OH oestrogens, is relevant to breast and endometrial cancer risk assessment in research literature, though clinical application of these ratios remains contested. No equivalent is obtainable from a 24-hour cortisol collection.

Australian Availability and Cost

24-hour UFC: Available through any major Australian pathology provider (Australian Clinical Labs, Dorevitch, Sullivan Nicolaides, and others) under MBS item 66833 (urinary cortisol). A valid referral from a GP or specialist is required. Out-of-pocket cost is typically nil to $30 depending on the provider and bulk billing availability. Results are returned within two to four business days. Creatinine is typically reported alongside cortisol for collection adequacy verification.

DUTCH test: Not available through Australian public pathology. The kit is available directly via Precision Analytical's Australian distributors or through integrative and functional medicine practitioners. The dried urine cards are collected at home and mailed to Precision Analytical's US laboratory. Turnaround is typically two to three weeks from receipt. Cost ranges from approximately $350–$500 AUD depending on which panel version is ordered (DUTCH Complete, DUTCH PLUS with the CAR spots, or DUTCH Cycle Mapping). No Medicare rebate applies; some private health insurers may provide partial reimbursement under extras cover, check with your fund directly.

For DHEA-S and adrenal reserve testing, note that DHEA-S serum measurement is separately available through standard Australian pathology under MBS and is not included in the DUTCH panel as a serum marker, the DUTCH measures DHEA metabolites in urine, which gives a different and complementary picture.

When to Use Each Test

Use the 24-hour UFC when:

• Cushing's syndrome is being investigated or ruled out by a GP or endocrinologist
• A Medicare-rebated, guideline-endorsed screening test is required
• The clinical question is whether total cortisol output is pathologically elevated
• Follow-up confirmation is needed after an abnormal overnight dexamethasone suppression test or late-night salivary cortisol

Use the DUTCH when:

• The clinical question involves HPA axis patterning rather than total output, diurnal curve, CAR, evening nadir
• Cortisol clearance and metabolism (enzyme activity) are relevant to the clinical picture
• Sex hormone metabolite profiling is needed alongside cortisol assessment
• The practitioner is investigating subclinical HPA dysregulation in the context of fatigue, burnout, insomnia, training recovery, or hormonal health
• Oestrogen metabolite ratios are part of the assessment

Do not use DUTCH results to rule in or rule out Cushing's syndrome. If a DUTCH panel returns elevated free cortisol values, this warrants referral for formal endocrine evaluation using guideline-endorsed tests, not a standalone clinical diagnosis.

Summary

The 24-hour urinary free cortisol and the DUTCH dried urine panel are complementary rather than competing tools. The UFC is the medically validated, Medicare-rebated standard for Cushing's syndrome screening, robust, guideline-endorsed, and appropriate for pathology exclusion in the hands of a GP or endocrinologist. The DUTCH addresses a different clinical domain entirely: the dynamic, timed, metabolite-rich picture of cortisol patterning, enzyme activity, and sex hormone metabolism that a single integrated number cannot convey.

Choosing between them is, in most cases, a question of whether the clinical question is how much cortisol is being produced over a day (UFC) or how is cortisol being secreted, metabolised, and responded to across the day (DUTCH). Understanding which question is being asked is the first step to ordering the right test.

Citations:

1. Nieman LK, Biller BMK, Findling JW, et al. The diagnosis of Cushing's syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008;93(5):1526–1540. https://academic.oup.com/jcem/article/93/5/1526/2598096

2. Newman M, Curran DA. Reliability of a dried urine test for comprehensive assessment of urine hormones and metabolites. Chem Cent J. 2021;15(1):25. https://pmc.ncbi.nlm.nih.gov/articles/PMC7962249/

3. Dried urine and salivary profiling for complete assessment of cortisol and cortisol metabolites. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC7744704/