Testosterone, Free (Adult Females, Children, or Individuals on Testosterone-Suppressing Hormone Therapy)
Provides a calculated value for free testosterone concentration using total testosterone measured by mass spectrometry. May be used to evaluate hyperandrogenism in children and cisgender females, monitor testosterone-suppressing hormone therapies (eg, antiandrogens or estrogens), evaluate testosterone status in individuals with protein-binding abnormalities, or evaluate hypogonadism in cisgender males.
To compare this test to other testosterone tests, refer to the ARUP Testosterone Tests Comparison table.
New York DOH Approval Status
Collect between 6-10 a.m.
Serum separator tube or green (sodium or lithium heparin).
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP standard transport tube. (Min: 0.8 mL)
After separation from cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 6 months
Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry/Electrochemiluminescent Immunoassay/Calculation
|Testosterone, Free by Mass Spec||
Free testosterone concentration is calculated using total testosterone (measured by mass spectrometry) and the binding constant of testosterone and sex hormone-binding globulin (SHBG).
For individuals on testosterone-suppressing hormone therapies (e.g., antiandrogens or estrogens), refer to cisgender female reference intervals. For a complete set of all established reference intervals, refer to ltd.aruplab.com/Tests/Pub/0081059.
Laboratory Developed Test (LDT)
Total testosterone and SHBG are measured and free testosterone is estimated from these measurements.
|Component Test Code*||Component Chart Name||LOINC|
|0081096||Testosterone, Free by Mass Spec||49042-5|