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  • Test Details
  • Lab Values
  • Clinical Significance
  • Treatment Options
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Test Code 1127

Test Details

Free Testosterone

Free testosterone is a measurement of testosterone that is not bound to SHBG. Testosterone is the most potent naturally occurring androgen and is produced by the interstitial cells of the testes in response to stimulation by luteinizing hormone (LH). Testosterone is also produced by the ovary and adrenal cortex in small amounts and is responsible for the regulation of gonadotropic secretion and spermatogenesis as well as the development of secondary sex characteristics.

Methodology

Calculation

Patient Preparation

None

Preferred Specimen

1.0 mL serum (0.5 mL minimum) collected in serum separator tube (SST / Tiger Top)

Alternate Specimen

None

Transport Temperature

Refrigerated (ship on frozen cold packs)

Stability

Refrigerated: 5 days

Lab Values

Lab Values

Free Testosterone

Sex/Age Optimal
Males >20 50.0-210.0 pg/mL
Females >21 1.0-8.5 pg/mL

 

Test Details
Clinical Significance

Clinical Significance

Free Testosterone

Testosterone is used in the diagnosis and treatment of the following disorders:1-4

  • Primary and secondary hypogonadism
  • Delayed or precocious puberty
  • Impotence in males
  • Hirsutism (excessive hair) and virilization (masculinization) in females due to polycystic ovaries, tumors and adrenogenital syndromes

References:

  1. Bhasin S, Cunningham GR, Hayes FJ, et al. Testosterone therapy in men with androgen deficiency syndromes: Endocrine Society clinical practice guidelines. J Clin Endorcinol Metab. 2010;95(6):2536-2559.
  2. Santen RJ, Allred DC, Ardoin SP, et al. Postmenopausal hormone therapy: an Endocrine Society scientific statement. J Clin Endocrinol Metab. 2010;95(7 Suppl 1):s1-s66.
  3. Kopper NW, Gudeman J, Thompson DJ. Transdermal hormone therapy in postmenopausal women: a review of the metabolic eff ects and drug delivery technologies. Drug Des Devel Ther. 2008;2:193-202.
  4. Goodman N, Cobin RH. Reproductive disorders. In: Camacho PM, Gharib H, Sizemore GW, eds. Evidence-Based Endocrinology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins. 2012:190-228.
Lab Values
Treatment Options

Treatment Options

Free Testosterone

  • Identify etiology of elevated or decreased free testosterone levels with physical assessment and additional diagnostic tests as indicated
  • Treatment is based on etiology of abnormal hormone level
Clinical Significance