5-Alpha Reductase Activity, 24-Hour Urine — Urinary Tetrahydrocortisol/Tetrahydrocortisone Profile
This 24-hour urine test measures cortisol-related steroid metabolites used to estimate 5-alpha reductase activity.
["The test evaluates 5-alpha reductase activity using steroid metabolites collected in urine over 24 hours."]
Key facts at a glance
- LOINC
- 82857-4
- Short code
- THF+5a-THC/THE 24h Ur-sRto
- Synonyms
- THF+5a-THC/THE 24h Ur-sRto
- Category
- liver
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 36
- Ref high
- 50
- Critical range
- 18 N/A – 60 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85014
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures tetrahydrocortisol and related steroid metabolites in urine collected for 24 hours. The results can be used to estimate the activity of the enzyme 5-alpha reductase.
Why might I need this test?
It may be ordered when reduced 5-alpha reductase activity is suspected, particularly in the evaluation of differences in sex development. It may also be used alongside other hormone and genetic tests.
How is the test performed?
Urine is collected into a special container for a full 24-hour period. The laboratory measures the steroid metabolites and may report a calculated value representing 5-alpha reductase activity.
How do I prepare for the test?
No fasting is usually required. Follow the collection instructions carefully, include all urine from the specified period, and ask your clinician before stopping any medicines. Strenuous exercise and unusual stress can affect steroid metabolite results.
Reference range
Adult males: 38-50%; Females: 36-44%N/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Lower-than-expected 5-alpha reductase activity may be associated with reduced enzyme function, including 5-alpha reductase deficiency. Abnormal results can also occur with adrenal disorders, changes in cortisol production, or certain medicines, so the result should be interpreted with symptoms, examination findings, and other tests.
Short name
24-hour urine 5-alpha reductase activity
Frequently asked questions
Is this the same as a serum hormone test?
What happens if part of the urine collection is missed?
Can medicines affect the results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy