Urinary Sex Steroid Metabolites: Sex- and Cycle-Related Differences, Normal Ranges, and Optimal Targets

Urinary sex steroid metabolite testing (sometimes ordered as a 24-hour urine steroid panel, or as a dried-urine panel such as the DUTCH test) measures the breakdown products of estrogen, testosterone, and progesterone that the liver produces and the kidneys excrete. It is a lab test category, not a drug or supplement, and it is used mainly in functional and integrative medicine practices rather than as a standard part of mainstream endocrinology or oncology workups.

The most discussed single marker in this panel is the ratio of 2-hydroxyestrone to 16-alpha-hydroxyestrone (the 2-OH/16-OH ratio). This ratio has a real research history as a possible breast-cancer risk marker, but the underlying prospective evidence is mixed rather than settled, and no major guideline body currently treats it as a validated screening or risk-stratification tool. Values on this panel also vary substantially by sex, menstrual-cycle day, menopausal status, and by which lab or platform performed the test, which limits how much a single number should be trusted in isolation.

The direct answer, with its boundary

Urinary sex steroid metabolites reflect cumulative hormone production and hepatic metabolism rather than a single-moment blood level, and normal values differ meaningfully by sex, cycle phase, and menopausal status. The 2-OH/16-OH estrogen ratio has been studied since the 1990s as a possible marker of breast-tissue proliferative risk, with some case-control and cohort studies reporting an association between lower ratios and higher risk and other prospective analyses failing to replicate it; because the literature is inconsistent and no endocrine or oncology guideline body has adopted the ratio as a validated risk or screening test, an individual result should be treated as one piece of context for a discussion with a clinician, not as a diagnostic number.

What the panel actually measures

Estrogens are hydroxylated at the C-2, C-4, or C-16 position of the steroid ring, producing three metabolite families with different receptor-binding behavior:

• 2-hydroxyestrone (2-OHE1): a weaker estrogen-receptor agonist, generally considered the more benign pathway.
• 16-alpha-hydroxyestrone (16-OHE1): retains meaningful estrogen-receptor binding and is the pathway of concern in proliferation hypotheses.
• 4-hydroxyestrone (4-OHE1): can form reactive quinone intermediates capable of DNA adduct formation in laboratory and animal models; this is the mechanistic rationale for tracking it, though its independent predictive value in humans is less studied than the 2-OH/16-OH ratio.

Phase-II methylation by catechol-O-methyltransferase (COMT) converts 2-OHE1 to 2-methoxyestrone. Low methyl-donor status (folate, B12) is proposed to slow this step, though the clinical significance of measuring this pathway routinely has not been established in outcome trials.

The panel typically also includes:

• Testosterone glucuronide/sulfate conjugates, reflecting androgen output.
• DHEA-S, the main adrenal androgen.
• Pregnanediol-3-glucuronide (PDG), the primary urinary progesterone metabolite, used as a marker of ovulation and luteal function.
• Androsterone and etiocholanolone, 17-ketosteroid metabolites reflecting androgen turnover.

The 2-OH/16-OH ratio: what is established and what is not

Established: the ratio can be measured reliably by mass spectrometry, and both metabolites vary with sex, cycle phase, adiposity, and hepatic enzyme activity.

Plausible but not established as clinically actionable: that steering the ratio upward (through diet, weight change, or supplement use) meaningfully changes an individual's breast-cancer risk. The biological hypothesis is reasonable, but a favorable shift in a urinary ratio is a surrogate marker, not a proven outcome.

Not established: a single validated cutoff that applies across labs, ages, and menopausal status, or that this ratio should replace or supplement mammography, genetic counseling, or standard oncology risk assessment. No FDA clearance, and no current major guideline from a body such as the Endocrine Society or professional oncology societies, endorses the 2-OH/16-OH ratio as a screening or diagnostic test. Where this article's earlier draft cited specific odds ratios and percentage changes from named studies, those figures could not be verified against a checkable primary source and have been removed rather than repeated as fact. A clinician or researcher who wants to rely on a specific published odds ratio should pull the original cohort paper rather than a secondhand figure.

Commercial labs commonly report a wide population reference range (often cited loosely as roughly 1 to 8) for the ratio in adults, with narrower target zones proposed by individual functional-medicine practices. Any specific numeric target quoted by a lab or clinician should be treated as that lab's own convention, not a universally validated cutoff, and confirmed against the reporting lab's own reference range rather than a number memorized from an article.

Sex differences

Men and women differ substantially in total estrogen production, which changes absolute metabolite output even when the underlying pathways are shared.

Premenopausal women produce far more estradiol daily than men, with most of it appearing in urine as conjugated estrone, estriol, and their hydroxylated derivatives. Output rises through the follicular phase and stays elevated through the luteal phase.

Men produce a much smaller daily quantity of estradiol, generated mainly by peripheral aromatization of testosterone, so male 2-OHE1 and 16-OHE1 excretion runs substantially lower than in premenopausal women. Testosterone glucuronide, by contrast, is the dominant androgenic metabolite in men and is far higher than in women. Normative data for the 2-OH/16-OH ratio in men are less robust than in women, largely because most of the prospective breast-cancer cohort research enrolled only women; extrapolating female-derived "optimal" ranges to men is not well supported.

Postmenopausal women lose the large majority of ovarian estrogen production, so total urinary estrogen metabolite output falls sharply. Because the pool shrinks unevenly, the proportional mix of metabolites can shift even as absolute amounts of each metabolite decline. This is one reason interpretation should use age- and menopausal-status-specific reference ranges rather than premenopausal norms.

Cycle-phase variation

Menstrual-cycle timing is one of the largest sources of day-to-day variability in urinary estrogen and progesterone metabolites, and testing without accounting for cycle day is a common source of misinterpretation.

Daily measurement studies of urinary oestrone glucuronide and pregnanediol glucuronide across normal menstrual cycles confirm that both metabolites rise and fall predictably across the cycle, with oestrone glucuronide peaking around ovulation and pregnanediol glucuronide rising sharply after ovulation through the luteal phase before falling before menses (Brown et al., variability of normal menstrual cycle profiles). This is the basis for using PDG as a practical marker of ovulation: a clear luteal rise supports that ovulation occurred, and a flat profile is consistent with an anovulatory cycle. Exact numeric cutoffs for "adequate" luteal PDG vary by lab and collection method, and a specific threshold should be confirmed with the performing lab rather than assumed from a general reference.

Separately, research measuring daily ovarian steroid metabolites alongside mood symptoms in early adolescents found meaningful within-person day-to-day variation in ovulatory cycles, and different patterns in anovulatory cycles (Marceau et al., 2026). This is a useful reminder that population-level "normal ranges" mask real biological variability between cycles and between individuals; it does not, by itself, establish adult female or male reference ranges, since the study population was early adolescents, a group with distinct reproductive maturation, not general premenopausal adults. A finding in adolescents should not be assumed to transfer directly to adult reference intervals.

Because of this variability, testing on a consistent, pre-agreed cycle day (commonly mid-to-late luteal phase for premenopausal women trying to interpret estrogen metabolites and confirm ovulation) is more useful for tracking change over time than a single test result interpreted against a general population range.

What animal and menopausal-transition data can and cannot tell us

Some of the mechanistic understanding of how estrogen and progesterone metabolites, and FSH, change around the menopausal transition comes from aged nonhuman primate models rather than direct human longitudinal data (Urbanski et al., aged macaque model). Animal models like this are useful for generating hypotheses about hormonal aging trajectories, but hormone metabolism, diet, and reproductive physiology differ enough between macaques and humans that specific numeric findings should not be read across as human reference values. Where this article describes postmenopausal patterns, it is describing the general, well-established direction of change (lower absolute estrogen metabolite output) rather than asserting specific quantitative targets drawn from animal data.

The DUTCH test and 24-hour urine collection

Two collection approaches are common in practice:

• 24-hour urine collection, sent to a standard clinical or specialty lab, measuring total metabolite output over a full day.
• Dried urine testing (DUTCH), which collects four to five timed urine spots on filter paper over one day, analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). LC-MS/MS avoids some cross-reactivity problems seen in older immunoassay-based urine panels. Details of the manufacturer's methodology and normative population are described on the test manufacturer's site; readers should treat manufacturer-published normative ranges as that company's own reference population rather than an independently validated clinical standard.

Results from a DUTCH panel and a standard 24-hour clinical lab panel are not directly interchangeable, because collection timing, units, and creatinine-correction conventions differ between platforms. Comparing a result to the wrong reference population is a common interpretation error.

When this test is ordered in practice

• Breast-cancer risk conversations: some functional-medicine and integrative clinicians use the 2-OH/16-OH ratio and 4-OHE1 level as part of a broader discussion about modifiable estrogen-metabolism factors in women with a personal or family history of hormone-receptor-positive breast cancer. This is a site- or practice-level judgment, not a guideline-endorsed screening protocol, and it does not replace mammography, genetic counseling, or oncology-directed risk assessment.
• Hormone therapy monitoring: some clinicians check baseline and follow-up panels when starting hormone therapy to see whether metabolism is shifting in an expected direction. Whether this changes long-term outcomes compared with monitoring by symptoms and standard labs alone has not been established in trial data.
• Cycle and fertility evaluation: a midluteal PDG rise is a reasonable, low-cost signal that ovulation occurred, and flat or low PDG in a woman trying to conceive is a reasonable prompt for further evaluation of luteal-phase adequacy.
• Androgen metabolism in men on testosterone therapy: some clinicians use androsterone and estrogen-metabolite output to get a sense of how much administered testosterone is being converted toward DHT versus estradiol, alongside standard serum monitoring, though serum-based monitoring remains the primary approach in most testosterone-therapy guidelines.

Factors that shift results, independent of underlying disease

• Diet: cruciferous vegetables and their extracts (indole-3-carbinol, DIM) are commonly reported to raise 2-hydroxylation activity; the general direction of this effect is plausible mechanistically, but a precise expected percentage change should not be assumed without checking the specific study design behind any number a clinician quotes.
• Body composition: adipose tissue is a site of aromatase activity and is generally associated with a shift toward the 16-hydroxylation pathway, so higher adiposity tends to track with lower ratios; weight change can shift the ratio, though the outcome significance of that shift is not established.
• Methylation status: low folate or B12 status is proposed to reduce conversion of 2-OHE1 to 2-methoxyestrone, but using this ratio to guide supplementation decisions is a functional-medicine practice pattern rather than a guideline-based one.
• Hormone formulation: oral estrogen undergoes first-pass hepatic metabolism and is generally expected to increase hepatic hydroxylation activity more than transdermal estrogen, which largely bypasses first-pass metabolism. The direction of this difference is pharmacologically plausible; specific percentage magnitudes quoted from a single small crossover study should be verified against the original paper before being treated as a settled number.
• Medications: broad-spectrum antibiotics can disrupt gut bacterial beta-glucuronidase activity, which affects estrogen deconjugation and enterohepatic recirculation, and can lower measured urinary estrogen metabolite output; tamoxifen and aromatase inhibitors substantially suppress estrogen metabolite production and require therapy-aware interpretation; proton pump inhibitors have a less well-characterized effect and warrant caution rather than a specific quantified adjustment.
• Renal function: creatinine correction adjusts for urine concentration but does not fully compensate for reduced clearance in chronic kidney disease. In patients with significantly reduced kidney function, results should be interpreted with nephrology input or supplemented with measured creatinine clearance.
• Muscle mass and protein intake: because creatinine output tracks muscle mass, people with low muscle mass or very low protein intake can show falsely elevated creatinine-corrected values; a timed 24-hour collection with measured creatinine output reduces this distortion.

A decision framework for interpreting an out-of-range result

This framework is for a reader (or clinician) who has an unexpected 2-OH/16-OH ratio, or another out-of-range urinary sex steroid metabolite value, and needs to decide what, if anything, to do next. It does not replace clinical judgment and is not a diagnostic algorithm.

Step 1: Confirm the comparison is valid.

• Was the sample compared to a reference range for the correct sex, menopausal status, and (for premenopausal women) approximate cycle day?
• Was it compared to the reporting lab's own reference population, not a number copied from a different platform (DUTCH versus 24-hour clinical lab ranges are not interchangeable)?
• If either answer is no, treat the result as uninterpretable until retested or recompared correctly, rather than acting on it.

Step 2: Rule out common non-disease explanations before assuming a "problem."

Step 3: Match the response to the strength of the evidence, not to the number alone.

• A single 2-OH/16-OH ratio outside a lab's stated range, with no personal or family cancer history and no fertility concern, is generally a discussion point for a routine visit, not an urgent finding.
• A flat or low midluteal PDG in someone actively trying to conceive is a reasonable prompt for a fertility-focused follow-up, since this marker has a more direct, established physiological meaning (confirming ovulation) than the estrogen-metabolite ratio does.
• A strong personal or family history of hormone-receptor-positive breast cancer, regardless of what this urine panel shows, should be managed through standard genetic counseling and oncology risk-assessment pathways; the urinary panel is not a substitute for that pathway and should not delay it.
• New or unexplained abnormal uterine bleeding, a breast lump, or other symptoms that could indicate a gynecologic or oncologic condition warrant direct evaluation regardless of urinary metabolite results, since this test is not diagnostic for those conditions.

Step 4: Decide on retesting, not on the first number.

• If a modifiable factor (diet, supplement, medication, cycle timing) plausibly explains an out-of-range value, correcting that factor and retesting is more informative than repeating the same interpretation on the same sample.
• Retesting after a deliberate change (diet, supplement, or hormone therapy adjustment) at roughly three to six months is a common practice pattern for tracking direction of change, though the ideal interval has not been established in trial data.

Common questions

Is the 2-OH/16-OH ratio a validated cancer screening test? No. It is a research-derived, biologically plausible risk marker with mixed prospective evidence, not a diagnostic or screening test. It should not replace mammography, genetic testing, or standard oncology risk assessment, and no major guideline body currently endorses a specific cutoff for clinical decision-making.

How does the menstrual cycle affect results? Both estrogen metabolites and PDG rise and fall across the cycle, with PDG rising sharply after ovulation through the luteal phase in ovulatory cycles. Testing on a consistent, pre-agreed cycle day (commonly mid-to-late luteal phase) makes results more comparable over time than an untimed single sample.

Can men have abnormal urinary estrogen metabolite patterns? Yes. Men aromatize testosterone to estradiol, and that estradiol goes through the same hydroxylation pathways studied in women, though at much lower absolute output. Reference data for men are less well validated than for women, since most of the underlying breast-cancer cohort research enrolled only women.

What is pregnanediol glucuronide (PDG) used for? PDG is the main urinary progesterone metabolite. A clear rise in the luteal phase is used as a practical, non-invasive indicator that ovulation occurred; a flat or low luteal profile in someone trying to conceive is a reasonable prompt for further fertility evaluation.

Does the DUTCH test give the same numbers as a standard 24-hour urine panel? No. The two platforms use different collection methods, units, and normative populations, so results are not directly comparable between them. Compare a result only to the reference range from the same platform that produced it.

What can throw off a result without indicating a health problem? Recent high cruciferous-vegetable intake or DIM/I3C supplementation, incorrect cycle-day timing, recent broad-spectrum antibiotic use, tamoxifen or aromatase-inhibitor therapy, low muscle mass affecting creatinine correction, and reduced kidney function can all shift results independent of underlying disease.

Evidence boundary summary

Established: urinary metabolites can be measured reliably with mass spectrometry; output differs by sex, cycle phase, and menopausal status; PDG is a reasonable practical marker of ovulation.

Plausible but unproven: that a favorable shift in the 2-OH/16-OH ratio, achieved through diet, weight change, or supplements, translates into a meaningfully lower personal breast-cancer risk.

Not established: a single validated numeric cutoff for the 2-OH/16-OH ratio that applies across labs, ages, and menopausal status; use of this panel as a screening or diagnostic tool for breast cancer; direct transfer of animal-model or adolescent-population findings to adult human reference ranges.

If you are considering this testing for a specific personal or family cancer-risk concern, a fertility evaluation, or hormone-therapy monitoring, discuss the specific question you are trying to answer with a clinician before ordering the panel, since the right test, timing, and interpretation depend heavily on that context.

References

• Brown JB. Monitoring of ovarian activity by daily measurement of urinary excretion rates of oestrone glucuronide and pregnanediol glucuronide, Part III: variability of normal menstrual cycle profiles. https://pubmed.ncbi.nlm.nih.gov/24170744/
• Marceau K, et al. Within-person associations between daily ovarian steroid levels and mood-related symptoms in ovulatory and anovulatory early adolescents (2026). https://pubmed.ncbi.nlm.nih.gov/41500030/
• Urbanski HF, et al. Estrogen and progesterone metabolites and follicle-stimulating hormone in the aged macaque female (2001). https://pubmed.ncbi.nlm.nih.gov/11717133/
• Precision Analytical, DUTCH test methodology overview (manufacturer site): https://dutchtest.com

This article is intended for general education and has not yet received qualified clinical review. It does not provide individualized diagnosis, dosing, or treatment recommendations. Discuss any hormone testing decision, and any results you receive, with a qualified clinician who knows your history.