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5-Alpha-Reductase, 24-Hour Urine — Mass Rate

Published: August 9, 2026Updated: August 16, 2026

A specialized 24-hour urine test measuring the amount of 5-alpha-reductase over time to help assess steroid metabolism.

Quick summary

["This test measures 5-alpha-reductase excretion and may help evaluate androgen metabolism when interpreted with other clinical findings."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
57620-7
Short code
5-A THF 2D p Dex 24h Ur-mRate
Synonyms
5-A THF 2D p Dex 24h Ur-mRate
Category
liver
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 is a specialized 24-hour urine test. It measures the amount of 5-alpha-reductase, an enzyme involved in converting testosterone to dihydrotestosterone, and reports the result as a mass rate.

Why might I need this test?

This test may be used in the evaluation of disorders involving androgen production or metabolism. Results are usually interpreted together with symptoms, other hormone tests, genetic testing, and other laboratory findings.

How is the test performed?

You collect all urine for a full 24-hour period in the container provided by the laboratory. The laboratory then measures 5-alpha-reductase and calculates the amount excreted per unit of time.

How do I prepare for the test?

Follow the laboratory's collection instructions carefully, including the exact start and finish times. Do not omit urine during the collection period, and tell the laboratory if any sample is accidentally missed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A result outside the expected range may indicate altered 5-alpha-reductase activity or a change in androgen metabolism. However, urine levels can also be affected by incomplete collection, medications, stress, and changes in hormone production, so an abnormal result does not establish a diagnosis by itself.

Short name

24-Hour Urine 5-Alpha-Reductase

Frequently asked questions

Is this the same as a testosterone or dihydrotestosterone test?
No. This test measures the amount of 5-alpha-reductase in urine, whereas testosterone and dihydrotestosterone tests measure the amounts of those hormones.
Why is a 24-hour urine collection required?
A 24-hour collection provides a more representative measure of how much of the substance your body excretes over a full day. A short urine sample may not reflect the usual daily amount.
Does an abnormal result diagnose a hormonal disorder?
No. The result must be interpreted with symptoms, other laboratory tests, and sometimes genetic testing because medications, stress, and collection problems can also affect the result.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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 16, 2026. · Read our editorial policy