Ordering Recommendation

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

This test is New York state approved.

Specimen Required

Patient Preparation

Collect between 6-10 a.m.

Collect

Serum separator tube or green (sodium or lithium heparin).

Specimen Preparation

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)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

EDTA plasma.

Remarks
Stability

After separation from cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 6 months

Methodology

Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry/Electrochemiluminescent Immunoassay/Calculation

Performed

Sun-Sat

Reported

1-5 days

Reference Interval

Test Number
Components
Reference Interval
  Testosterone by Mass Spec
Age
Male (ng/dL)
Female (ng/dL)
Premature (26-28 weeks) 59-125 5-16
Premature (31-35 weeks) 37-198 5-22
Newborn 75-400 20-64
1-5 months 14-363 Less than 20
6-24 months Less than 37 Less than 9
2-3 years Less than 15 Less than 20
4-5 years Less than 19 Less than 30
6-7 years Less than 13 Less than 7
8-9 years 2-8 1-11
10-11 years 2-165 3-32
12-13 years 3-619 6-50
14-15 years 31-733 6-52
16-17 years 158-826 9-58
18-39 years 300-1080 9-55
40-59 years 300-890 9-55
60 years and older 300-720 5-32
Premenopausal (18 years and older) Not Applicable 9-55
Postmenopausal Not Applicable 5-32
Tanner Stage I 2-15 2-17
Tanner Stage II 3-303 5-40
Tanner Stage III 10-851 10-63
Tanner Stage IV-V 162-847 11-62

  Testosterone, Free by Mass Spec
Age
Male (pg/mL)
Female (pg/mL)
1-6 years Less than 0.6 Less than 0.6
7-9 years 0.1-0.9 0.6-1.8
10-11 0.1-6.3 0.1-3.5
12-13 0.5-98.0 0.9-6.8
14-15 3-138.0 1.2-7.5
16-17 38.0-173.0 1.2-9.9
18 years and older 47-244 Not Applicable
18-30 Not Applicable 0.8-7.4
31-40 Not Applicable 1.3-9.2
41-51 Not Applicable 1.1-5.8
Postmenopausal Not Applicable 0.6-3.8
Tanner Stage I Less than or equal to 3.7 Less than 2.2
Tanner Stage II 0.3-21 0.4-4.5
Tanner Stage III 1.0-98.0 1.3-7.5
Tanner Stage IV 35.0-169.0 1.1-15.5
Tanner Stage V 41.0-239.0 0.8-9.2

  Sex Hormone Binding Globulin
Age
Male (nmol/L)
Female (nmol/L)
1-30 days 13-85 14-60
31-364 days 70-250 60-215
1-3 years 50-180 60-190
4-6 years 45-175 55-170
7-9 years 28-190 35-170
10-12 years 23-160 17-155
13-15 years 13-140 11-120
16-17 years 10-60 19-145
18-49 years 17-56 25-122
50 years and older 19-76 17-125
Tanner Stage I 26-186 30-173
Tanner Stage II 22-169 16-127
Tanner Stage III 13-104 12-98
Tanner Stage IV 11-60 14-151
Tanner Stage V 11-71 23-165

Interpretive Data

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/0081056.

Compliance Category

Laboratory Developed Test (LDT)

Note

Please refer to individual components for stability of sample for this test.

The concentration of free testosterone is derived from a mathematical expression based on the constant for the binding of testosterone to sex hormone binding globulin.

Hotline History

N/A

CPT Codes

84402; 84403; 84270

Components

Component Test Code* Component Chart Name LOINC
0081058 Testosterone by Mass Spec 2986-8
0081096 Testosterone, Free by Mass Spec 49042-5
0099375 Sex Hormone Binding Globulin 13967-5
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

  • Testosterone Free
Testosterone, Free and Total, Includes Sex Hormone-Binding Globulin (Adult Females, Children, or Individuals on Testosterone-Suppressing Hormone Therapy)