Androsterone Test

Most hormone testing focuses on testosterone, the headline androgen. But your body is constantly converting testosterone and related steroids into downstream products, and those byproducts often tell a richer story about what is actually happening in your tissues than the parent hormones do. Androsterone is one of those byproducts.

This test measures androsterone in dried urine, a snapshot of how much androgen your body has produced, used, and broken down recently. It is not a primary sex hormone you act on directly. It is a fingerprint of androgen biosynthesis and clearance, and the pattern it reveals can flag adrenal imbalances, conditions like polycystic ovary syndrome, or shifts in how your body handles testosterone as you age.

What Androsterone Actually Is

Androsterone is a C19 steroid (a steroid built around a 19-carbon backbone, the same family that includes testosterone). Your body makes it primarily through two routes. The classic route takes testosterone, converts it to DHT (dihydrotestosterone, the most active form of testosterone in tissue), then breaks DHT down through a series of enzymes that ultimately yield androsterone. A second route, called the backdoor pathway, skips testosterone entirely and routes upstream precursors like 17-hydroxyprogesterone directly to androsterone.

Androsterone itself is largely inactive. It does not bind strongly to the androgen receptor the way testosterone or DHT does. Instead, it represents the end of the line, the product your liver, adrenal glands, and peripheral tissues make to clear active androgens out of circulation. Because of this, levels reflect total tissue-level androgen turnover, not just what is circulating at a given moment.

Why Tracking Androsterone Matters

A standard testosterone test gives you a single snapshot of one hormone in the blood. Androsterone, measured in dried urine, captures something different: how active your androgen pathways are across the day, including the contribution of adrenal precursors that testosterone testing alone misses. Two people can have identical testosterone levels but very different androsterone signatures, suggesting different rates of conversion, clearance, or alternative pathway use.

Plasma androsterone concentrations also drop substantially with age. Conjugated forms of androsterone (the sulfate and glucuronide versions your body makes during clearance) decline by roughly 40 to 70 percent between the 20 to 30 and 70 to 80 age brackets, mirroring the broader fall in adrenal androgen output. These findings come from plasma studies, not dried urine, but the underlying age-related decline in androgen turnover is consistent across matrices.

Androgen Excess and PCOS

In women with polycystic ovary syndrome (PCOS), urinary steroid profiling consistently shows higher androgen metabolite excretion than in unaffected women. In a pilot study of 107 women (41 with PCOS and 66 controls), 24-hour urinary steroid profiling identified a multi-metabolite signature, including androgen metabolites and their ratios, that distinguished PCOS from controls. Separate work has shown that urinary 11-hydroxyandrosterone, an 11-oxygenated version of androsterone, is elevated in PCOS and contributes to the dominant 11-oxygenated androgen pool seen in the condition.

A different angle on the same condition: in obese women with PCOS, the ratio of androsterone glucuronide (the inactive cleared form) to DHEA-S (an adrenal precursor) is elevated compared with non-obese women and controls. This ratio is thought to reflect more active 5-alpha-reductase, the enzyme that drives testosterone toward DHT and downstream metabolites. In plain terms, the obese-PCOS pattern suggests more aggressive conversion of androgens into their potent and then cleared forms.

Adrenal Disorders and Bone Health

Androsterone can fall when adrenal androgen production is suppressed. In premenopausal women with mild autonomous cortisol secretion (a condition where a benign adrenal tumor quietly overproduces cortisol), androsterone glucuronide tends to be lower. A study of 158 patients found that women with higher androsterone glucuronide had better trabecular bone score, a measure of bone microarchitecture. The implication is that the same hormonal shift that drives cortisol excess also strips out the protective adrenal androgens that help maintain bone.

Congenital adrenal hyperplasia (CAH), a genetic condition where the adrenal glands cannot make cortisol normally, produces a different pattern. Urinary androsterone is elevated, and the ratio of androsterone to etiocholanolone (another androgen byproduct) rises, indicating that the body is routing precursors through the backdoor pathway to compensate.

Prostate Cancer and Androgen Deprivation

In men with prostate cancer who undergo androgen deprivation therapy (medical castration used to starve the tumor of testosterone), androsterone and its conjugates drop sharply. A study of 99 men showed that under castration, residual DHT in circulation becomes more closely tied to androsterone via the backdoor pathway, meaning the body finds alternate routes to keep some androgen flowing even after standard treatment.

Separately, in 160 men with non-metastatic prostate cancer on androgen deprivation, larger drops in androsterone sulfate were linked to more sleep-related impairment and fatigue, suggesting that the depth of androgen suppression tracks with how patients feel during treatment.

Reconciling a Tricky Finding

Higher androsterone is not always good and lower is not always bad. In the bone health study above, more androsterone glucuronide correlated with better bones. But in 579 postmenopausal women, higher androsterone glucuronide and total glucuronide metabolites were associated with increased risk of non-serous ovarian cancer. The same marker, two different stories. The cleanest framework: androsterone is a phenotype indicator, not a good number or bad number. Its meaning depends on what you are looking for and where the androgen activity it reflects is occurring. This is one reason it is not used as a standalone screening test and should always be interpreted alongside other hormones and clinical context.

Reference Ranges

Androsterone is an exploratory marker. There are no universally standardized clinical cutpoints for dried-urine androsterone the way there are for cholesterol or HbA1c. Most published thresholds come from individual research cohorts using specific assay methods (typically mass spectrometry, a lab technique that identifies molecules by their mass), and they vary by age, sex, time of day, and the way the sample was collected. The most reliable orientation is your own trend within the same lab.

These descriptions are orientation, not diagnosis. Your lab will report a specific reference interval based on its assay. Compare your results to that range and, more importantly, to your own previous readings.

Tracking Your Trend

A single androsterone reading is the start of a story, not the conclusion. Hormone metabolites fluctuate with the time of day, the day of the cycle in premenopausal women, recent stress, and even the sample collection technique. A classic study documented meaningful daily and day-to-day variation in plasma androsterone within the same individuals, which means one elevated or low value should be confirmed before any major interpretation.

Get a baseline, then retest in 3 to 6 months if you are making changes (treating a known hormone condition, addressing adrenal stress, or starting therapies that affect androgen pathways). After that, annual or twice-yearly tracking is reasonable for people with ongoing hormone questions. The within-person variation for steroid hormones in general runs in the 15 to 20 percent range, so small shifts on a single test do not necessarily mean anything has changed biologically.

What an Abnormal Result Should Make You Do Next

Androsterone alone does not give you a diagnosis. If your result is unusually high or low, it should prompt a wider hormone workup rather than immediate action on the number itself.

• High androsterone in a woman with irregular cycles, acne, or hair growth: pair with testosterone, free testosterone, SHBG (sex hormone binding globulin), DHEA-S, and 17-hydroxyprogesterone to evaluate for PCOS or non-classic CAH. An endocrinologist or reproductive endocrinologist is the right next step.
• Low androsterone in someone with weight gain, central fat, and fatigue: pair with cortisol (saliva or 24-hour urine) and DHEA-S to assess for autonomous cortisol secretion. An endocrinologist should be involved.
• Low androsterone in a man on testosterone therapy or after prostate cancer treatment: pair with total and free testosterone, DHT, and estradiol. This is expected on androgen deprivation but worth confirming alongside symptom tracking.
• Any extreme reading without a clinical explanation: repeat the test, ideally at the same time of day and using the same collection protocol, before pursuing further workup.

When Results Can Be Misleading

A few common situations can shift a single androsterone reading without indicating any real underlying problem.

• Time of day: androsterone and other 17-ketosteroids show daily variation. Collecting at a different time than your baseline can produce a misleading shift.
• Day-to-day biological fluctuation: documented within-person variability means two readings taken a week apart can differ even when nothing has changed.
• Investigational AKR1C3 inhibitors: a phase 1 trial showed that the experimental drug BAY1128688 (a selective AKR1C3 inhibitor) raised serum androsterone roughly threefold in premenopausal women over 14 to 28 days. This is a drug effect on pathway routing, not a sign of disease.
• Age and sex: men and women have different baseline ranges, and levels decline meaningfully with age. A value that is low for a 25-year-old may be normal for someone in their 70s.