Clinical Insights · Hormone Testing
Serum, saliva or urine?
Why we choose DUTCH testing at
The Bespoke Clinic
If you have ever wondered whether blood, saliva or urine is the best way to submit a hormone imbalance test, you are not alone. At The Bespoke Clinic, we use DUTCH testing because it provides a far more complete picture of hormone levels, metabolism and cortisol patterns. This is a guide to the three main approaches to hormone testing and why the right choice depends on what question you’re actually asking.
Patients often arrive having done their own research, which we welcome. A common question we hear is: “I’ve heard of ZRT saliva testing. Why did you choose a urine test instead?” It’s a fair question, and it deserves a real answer rather than a dismissal.
The short answer is: there is no single “best” method. Each approach, be it serum (blood), saliva, or dried urine, has genuine strengths and limitations. What matters is matching the right tool to the right clinical question. Here at The Bespoke Clinic, we use DUTCH dried urine testing for most hormone assessments, and we want to explain why, including where it falls short and where saliva or serum may be more appropriate.
First, what are we actually measuring?
All three methods measure steroid hormones (oestrogen, progesterone, testosterone, cortisol, DHEA), but they capture different things:
- Measures total hormone (mostly protein-bound)
- Snapshot at one moment in time
- Requires a phlebotomy appointment
- Gold standard for baseline diagnostics
- Best for: diagnosing deficiency, TRT dosing
- Weaker for: transdermal oestradiol monitoring
- Measures free (unbound) hormone
- Non-invasive, at-home collection
- Can capture diurnal patterns
- Best for: cortisol rhythm assessment
- Problem: dramatically inflated readings after topical hormone application
- No evidence these elevated values reflect tissue exposure
- Measures hormone metabolites over time
- 4-spot at-home collection across one day
- Shows how hormones are processed by the body
- Best for: metabolite patterns, transdermal oestradiol monitoring, HPA axis
- Not optimal for: baseline TRT deficiency diagnosis
The saliva debate: what the research actually shows
Saliva testing has been taught within integrative medicine for over 25 years as the gold standard for monitoring topical hormone creams and gels. The logic was appealing: free hormones in saliva represent bioavailable, tissue-active hormone, the fraction “actually doing something” in the body. ZRT Laboratory, one of the most respected names in this space, built their reputation on this principle.
However, a landmark peer-reviewed paper published in 2026 in Frontiers in Reproductive Health, authored by Mark Newman and colleagues at Precision Analytical, the creators of DUTCH, has comprehensively challenged this view for sex hormone monitoring.
Key finding
After reviewing over 100 published studies, the authors could not find a single study where elevated salivary testosterone values after topical application corresponded to clinical outcomes: not bone density, lean mass, sexual function, or androgen symptoms. Every clinical change tracked with serum levels, not saliva levels.
However, a landmark peer-reviewed paper published in 2026 in Frontiers in Reproductive Health, authored by Mark Newman and colleagues at Precision Analytical, the creators of DUTCH, has comprehensively challenged this view for sex hormone monitoring.
This is clinically significant because while serum barely moves, when transdermal testosterone is applied, saliva readings spike dramatically and often into supraphysiological territory. If you’re using saliva to guide dosing, you may dramatically under-dose your patient, believing they’re already “flooded” with hormone when tissue levels are actually still low.
The paper also included new real-world data from hundreds of women on transdermal testosterone: those with supraphysiological saliva levels reported no more androgenic symptoms (acne, hair loss, irritability etc.) than women with normal saliva levels. The elevated saliva simply wasn’t telling us what we thought it was.
So does saliva have no value at all?
Not quite, and this nuance matters. Saliva remains a well-validated tool for cortisol rhythm assessment. For cortisol specifically, saliva provides an instantaneous snapshot that complements the averaged picture you get from urine.
The problem is specific to monitoring topically applied sex hormones. Here, the saliva signal appears to reflect a local skin/salivary gland artefact rather than systemic tissue exposure. It’s not that saliva testing is “wrong”, it’s that it’s the wrong tool for this particular question.
What about oestradiol and progesterone?
The 2026 paper focused primarily on testosterone, but the authors comment that oestradiol behaves similarly. Saliva values inflate well above serum and urine with transdermal application, and there is currently no published clinical evidence that those elevated values correspond to meaningful outcomes. This mirrors what DUTCH’s own data has shown for years.
Progesterone is the most complex case of all, and frankly, no method does it perfectly. Serum levels don’t scale predictably with transdermal doses. Urine captures metabolites but not the parent hormone. Saliva inflates dramatically; 100mg of transdermal progesterone can push salivary levels far beyond premenopausal norms, while urine levels may remain below the premenopausal range. For now, clinical judgement of symptoms, cycle patterns, and endometrial monitoring, where relevant, remains an essential part of the progesterone picture alongside any lab testing.
Why we use DUTCH Testing at The Bespoke Clinic
The DUTCH test uses dried urine collected across four time points in a single day. This means it captures an average picture of hormone exposure rather than a single moment; particularly useful for hormones that fluctuate through the day, including cortisol and oestradiol. Crucially, it also maps hormone metabolites, which serum and saliva cannot do.
| Clinical question | Best method |
|---|---|
| Diagnosing testosterone deficiency / baseline TRT assessment | Serum |
| Monitoring testosterone cream or gel dosing | Serum (primary) + DUTCH (adjunct) |
| Monitoring transdermal oestradiol cream or gel | DUTCH or serum, not saliva |
| Cortisol rhythm / HPA axis patterns | DUTCH or saliva, both valid |
| Oestrogen metabolism (2-OH vs 16-OH pathway etc.) | DUTCH only |
| Transdermal progesterone monitoring | No method fully reliable, lean on symptoms |
| Comprehensive hormonal picture including HPA axis + metabolites | DUTCH |
Hormone metabolism matters deeply in functional medicine. Two patients can have identical serum oestradiol levels yet completely different risks depending on whether they’re metabolising oestrogen down the protective 2-OH pathway or the more problematic 16-OH route. Only urine testing reveals this. Similarly, understanding the HPA-cortisol-androgen axis as a whole (how stress affects sex hormones and vice versa) requires the breadth of markers that DUTCH provides.
What this means for you as our patient
When we order a DUTCH test, we are not following a trend or cutting corners, we are using the most information-rich tool currently available for the clinical questions we are asking. We have serum testing available and use it where it is clearly the right choice. We do not dismiss saliva testing; for cortisol rhythm, it remains a valuable modality.
What we do not do is use a method uncritically because it has been taught as standard for 25 years. The science in this field is evolving, and a 2026 peer-reviewed paper has substantially shifted our understanding of what saliva testing can and cannot tell us when patients are using topical hormone preparations.
We think you deserve to understand the reasoning behind every clinical decision we make. If you have questions about your specific test, your results, or why we chose one method over another, please ask. That conversation is always welcome.
A note on integrative medicine and evidence
One of the things we value most about functional and integrative medicine is its willingness to ask deeper questions about the body. But that same spirit of enquiry means we must be willing to update our practices when the evidence evolves, even when that challenges long-held assumptions. The current evidence supports DUTCH as the most clinically comprehensive at-home hormone test for most of our patients. We review this position as new research emerges.
Sources: Newman MS et al. (2026). Alternatives to serum testing for transdermal testosterone monitoring. Frontiers in Reproductive Health 8:1804311. DUTCH Test clinical articles, dutchtest.com. ZRT Laboratory clinical resources, zrtlab.com.
