Ordering Recommendation

Aids in the evaluation of suspected hypogonadism in men with a total testosterone level at the lower limit of the normal range. Not recommended for use in women and children.

Mnemonic
FREE T2
Methodology

Quantitative Electrochemiluminescent Immunoassay
Total Testosterone and SHBG are measured and free testosterone is estimated from these measurements.

Performed

Sun-Sat

Reported

Within 24 hours

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation

Collect specimen between 6-10 a.m.

Collect

Serum separator tube or green (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: 0.4 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

EDTA plasma.

Remarks
Stability

After separation from cells: Ambient: 48 hours; Refrigerated: 1 week; Frozen: 2 months

Reference Interval

Male:
14-15 years:  3-138 pg/mL
16-17 years:  38-173 pg/mL
18 years and older: 47-244 pg/mL

Tanner Stage IV:  35-169 pg/mL
Tanner Stage V:  41-239 pg/mL

Interpretive Data

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 (SHBG).

Compliance Category

FDA

Note

This test is not recommended for females or children.  For testing on females or children refer to Testosterone Free, Females or Children (0081059).

Hotline History
N/A
CPT Codes

84402

Components
Component Test Code* Component Chart Name LOINC
0070113 Testosterone, Free Calculation 2991-8
* 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
  • Free testosterone
  • serum testosterone free
Testosterone Free, Adult Male