Dihydrotestosterone (DHT), Free, LC/MS/Dialysis

CPT: 84999
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Test Details


  • Free 5-α-dihydrotestoterone


Dihydrotestosterone measurement is used to diagnose 5α-reductase deficiency and for the evaluation of androgen utilization. Dihydrotestosterone is produced by the reduction of testosterone by 5α-reductase in the target organs. Circulating dihydrotestosterone is tightly bound to sex hormone-binding globulin. The free fraction represents the dihydrotestosterone available to act on tissues.


This test was developed, and the performance characteristics determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA).


Equilibrium dialysis, high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS-MS)

Specimen Requirements


Serum (preferred) or plasma, frozen


3 mL

Minimum Volume

1.2 mL (Note: This volume does not allow for repeat testing.)


Red-top tube, gel-barrier tube, or green-top (heparin) tube


Separate serum or plasma from cells within four hours of collection. Send serum or plasma in a plastic transport tube. Transfer specimen to a plastic transport tube before freezing. To avoid delays in turnaround time when requesting multiple test on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions

Freeze. Stable at room temperature, refrigerated, or frozen for 14 days. Freeze/thaw cycles: stable x6

Causes for Rejection

EDTA plasma; grossly hemolyzed, icteric, or lipemic sample


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
504026 DHT, Free, LCMS/Dialysis 500143 Dihydrotestosterone ng/dL 1848-1
504026 DHT, Free, LCMS/Dialysis 504028 DHT, Percent Free Dialysis % 13882-6
504026 DHT, Free, LCMS/Dialysis 504029 DHT, Free pg/mL 14047-5

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