Urine Hormone Metabolites

What Urine Hormone Metabolites Measure

A hormone doesn't circulate forever. The liver and kidneys inactivate it, and the leftovers exit in urine.^[3] Those leftovers are the metabolites, and each one is a record of the hormone that came before it. The two fertility metabolites, PdG and E3G, have their own entries. This one covers the rest of the urinary panel.

Urinary cortisol. The fraction of cortisol that circulates unbound to its carrier protein filters into urine unchanged, so a 24-hour urinary free cortisol collection gives an integrated picture of cortisol output across a full day and night.^[2] It's the classic example of urine as a summary rather than a snapshot.

aMT6s. Melatonin's primary urinary metabolite is 6-sulfatoxymelatonin, or aMT6s. Circadian researchers measure it in urine collected over 24 to 48 hours to estimate the overall timing and amount of melatonin production, a practical alternative to sampling blood through the night with a catheter.^[1]

8-OHdG. This one isn't a hormone metabolite at all. It's a DNA one. When oxidation damages DNA, repair processes excrete the oxidized products in urine, and 8-OHdG is considered a biomarker of that damage.^[4] Researchers have used it widely to study oxidative stress.^[5] To be clear about its status: it's a research marker, not routine care. A 2020 meta-analysis concluded that background ranges still need defining before it can serve as a standard measure of oxidative stress.^[4]

How They're Measured

Labs measure these markers with immunoassays and chemical methods, run on anything from a single spot sample to a timed overnight collection to a full 24-hour jug.^[1][4] You'll see them in research studies, in specialty hormone panels, and in some mail-in kits that report urinary cortisol or melatonin metabolites.

Why People Track Urine Hormone Metabolites

The draw is the time dimension. Cortisol and melatonin both swing hard across the day, so a single blood value catches one point on a moving curve. A urine collection averages over the whole window, which is why researchers reach for aMT6s when they want a person's overall melatonin output and for urinary free cortisol when they want a full day of cortisol in one number.^[1][2] People who get these results back, from a study, a clinician-ordered panel, or a mail-in kit, often want them stored somewhere alongside the rest of their health data.

For how urine tests fit alongside blood draws and strips, see our guide to at-home hormone tests.

How Go Go Gaia Tracks Urine Hormone Metabolites

Go Go Gaia's lab upload accepts urine cortisol, melatonin (aMT6s), and 8-OHdG results, along with urine iodine, testosterone, and DHEA-S. Upload a report or enter a value and the app files it under the right analyte, converts units, and charts each marker over time next to your serum labs and cycle data.

What the Research Shows

A consensus paper on measuring melatonin in humans describes aMT6s, collected every 2 to 8 hours across a 24- to 48-hour period, as a practical method to estimate the global timing and amount of melatonin production.^[1] The Endocrine Society's clinical practice guideline describes 24-hour urinary free cortisol the same way for cortisol: an integrated assessment of secretion over a 24-hour period, measuring the cortisol that filters into urine unbound.^[2]

For 8-OHdG, a 2020 systematic review and meta-analysis pooled urinary values across healthy adults, found higher concentrations in smokers, and called for defined background ranges before the marker can be used as a standard measure of oxidative stress.^[4] An earlier review reached a similar place, treating 8-OHdG as a research biomarker of oxidative DNA damage used to study exposures like tobacco smoke and heavy metals.^[5]

Related Terms

Frequently Asked Questions

Educational information based on published sources. Not medical advice. For personal concerns, please consult your doctor.

Is a urine hormone test the same as a blood hormone test?

No. A blood test measures the hormone itself at one moment. A urine test usually measures what's left after the body has processed the hormone, accumulated over however long the urine collected. The two routes answer different questions: blood gives a snapshot, urine gives a summary of the collection period.^[1][2]

What is aMT6s?

aMT6s (6-sulfatoxymelatonin) is the primary urinary metabolite of melatonin. Circadian researchers measure it in urine collected over 24 to 48 hours to estimate the overall timing and amount of a person's melatonin production without drawing blood through the night.^[1]

Is 8-OHdG part of routine medical care?

No. 8-OHdG is a research marker of oxidative DNA damage. A 2020 meta-analysis concluded that background ranges still need to be defined before it can serve as a standard measure of oxidative stress, so it appears in studies and some specialty panels rather than routine checkups.^[4]