EndoAxis Clinical Team
Now that we’ve had a thorough review on the hormones, their rhythms, and the pros and cons to lab methodology, let’s review how best to test sex and stress hormones.
Is there an ideal “best” test?
The honest answer: no single method is best in all scenarios.
Different matrices capture different aspects of hormone physiology — absolute levels, free/bioavailable fractions, metabolites, or diurnal patterns. The most accurate approach depends entirely on the clinical question you’re trying to answer. Think of hormone testing like viewing a patient from multiple camera angles:
- Serum = a snapshot with precise quantitative values. Protein bound. Single point in time.
- Saliva = a snapshot of free hormone at the tissue level. Also a single point in time.
- Dried urine = a time-lapse that shows hormone patterns, metabolism, and clearance.
The key is matching the test to what you’re actually trying to understand.
Serum Testing
What serum is best for
- Diagnostic thresholds:
Thyroid, prolactin, LH/FSH, estradiol, progesterone (mid-luteal), testosterone, SHBG, DHEA-S. - Monitoring therapeutic blood levels of hormones for tracking postmenopausal bHRT load in the body. Most helpful for diagnosis and therapeutic outcomes.
- Any situation that requires absolute quantification using well-validated reference ranges.
Strengths
- Gold-standard for most endocrine societies.
- Highly accurate quantification (methodology matters)
- Good for high-concentration hormones like LH/FSH.
- Essential for ruling out pathology: PCOS, hypogonadism, menopause, pituitary issues.
Limitations
- Testosterone and estrogen accuracy in women can be poor with some immunoassays — LC/MS is strongly preferred.
- Mostly measures protein-bound hormone, not the active free fraction.
- Cannot reflect diurnal rhythm except with multiple blood draws.
- Poor at capturing metabolites, like estrogen pathways.
Saliva Testing
What saliva is best for:
- Free cortisol patterning across the day (4-point or 5-point).
- Stress response / CAR (cortisol awakening response).
- Free sex steroids when looking at tissue-level exposure.
Strengths
- Non-invasive and allows pattern testing.
- Captures free, unbound hormone, which reflects what’s available to tissues.
- Excellent for cortisol circadian rhythm and CAR dynamics.
- Useful during cycling to track relative luteal vs follicular changes.
Limitations
- Contamination risk (topical hormones, hydrocortisone creams). Gingivitis and
- periodontitis will also interfere with accuracy of sex hormones results.
- Not reliable for absolute sex-steroid quantification.
- Estradiol in perimenopause or low ranges can be too low for accurate salivary
- detection.
- Does not provide metabolite information.
Best use:
- Free cortisol 4-point testing and adrenal rhythm. Secondary use: free
- progesterone/testosterone trends, not absolute values.
Dried Urine Testing (Dutch-Type)
What dried urine is best for
- Hormone metabolites (especially estrogen: 2-OH, 4-OH, 16-OH pathways).
- Cortisol metabolites (11β-HSD activity, cortisone/cortisol conversion).
- Methylation assessment via 2-methoxy estrogens.
- Time-averaged exposure to sex hormones.
- Dry urine testing is the only testing method that can monitor if hormone replacement therapy is being utilized and detoxified by the body.
Strengths
- Gives a multi-dimensional picture — levels + patterns + metabolism.
- Excellent for:
- Cycling women
- Estrogen detox patterns
- Androgen metabolism (5α vs 5β pathways)
- Chronic stress (cortisol metabolites)
- Captures free cortisol rhythm + total cortisol output, which serum and saliva alone cannot do.
Limitations
- Results can be influenced by kidney function and fluid intake (though creatinine adjustment helps).
- Oral hormones will contaminate results due to first-pass metabolism
- UGT deletions can reduce accuracy of testosterone (5a-androstanediol andDHEA+ metabolites are not affected).
- Complex data! Difficult to merge it all together to make sense for therapeuticintervention.
Best use:
- To review hormone patterns and daily metabolic activity, not absolute values.
- It excels in functional medicine–style interpretation: why hormones are behaving a certain way, not just what the level is.
Why EndoAxis Uses DUTCH
EndoAxis has chosen to work with the DUTCH test as DUTCH results show more than the absolute values of hormones. With DUTCH testing, we are able to see patterns of hormone production and how these hormones move through the body and how they are cleared through the body. This data offers superior insight into enzyme function and hormone patterning which allows deeper evaluation for a more comprehensive treatment approach. DUTCH testing is validated and peer-reviewed to offer the highest standard for hormone interpretation. EndoAxis utilizes this gold standard testing to offer providers and patients the best for interpretation and treatment outcome. If you want to be part of the movement for better patient outcomes, enhanced understanding of testing, and improved clinical competency, join EndoAxis today!
Join us next week to for: Just as important as the type of testing is the way hormones are tested.
