Serum Testosterone (Total & Free)
Also known as: Total Testosterone, Free Testosterone, Male Hormone Panel, Serum Androgen Test
Parameters Measured in the Report
A breakdown of individual biomarkers and biological reference intervals typically found in your report:
| Biomarker | Standard Range | Unit | What It Means |
|---|---|---|---|
Total Testosterone (Males) (Total T) | Adult Males: 300–1,000 (Deficient: < 300 on repeated morning tests) | ng/dL | Total concentration of circulating androgen including SHBG-bound and free fractions. |
Total Testosterone (Females) (Female Total T) | Adult Females: 15–70 (Elevated in PCOS: > 70) | ng/dL | Evaluates androgen excess, hirsutism, and virilization in women. |
Free Testosterone (Males) (Free T) | Adult Males: 5.0–21.0 | ng/dL (or pg/mL) | The active, unbound fraction directly accessible to androgen receptors. |
* Note: Reference ranges may vary slightly between testing instruments and reagent kits. Always refer to the reference interval printed on your specific pathology report.
Clinical Focus
Primary androgen steroid hormone: Total testosterone (protein-bound) and Free testosterone (biologically active).
Sample & Specimen
Venous blood (Serum tube)
Fasting Protocol
Morning collection between 7:00 AM and 10:00 AM is required due to circadian peaks in testosterone production.
Turnaround Time
12–24 hours
What Is This Test?
Why Did Your Doctor Order This Test?
Physicians routinely prescribe the Testosterone in the following clinical scenarios:
How to Prepare Before Your Test
- Blood must be collected in the early morning (7:00 AM–10:00 AM) when testosterone levels peak.
- Fasting for 8–10 hours is recommended, as acute glucose intake temporarily suppresses serum testosterone levels by up to 25%.
Understanding Your Results
What higher or lower readings generally mean in clinical practice:
If Values Are Higher Than Normal
Elevated testosterone in women (>70 ng/dL) is a hallmark of PCOS, congenital adrenal hyperplasia, or ovarian/adrenal androgen-secreting tumors. In men, very high levels are typically seen in exogenous testosterone or anabolic steroid use.
If Values Are Lower Than Normal
Total testosterone below 300 ng/dL on two separate morning blood draws confirms Male Hypogonadism (Low T), contributing to fatigue, low libido, erectile dysfunction, osteopenia, and diminished muscle tone.
Frequently Asked Questions
Why does testosterone have to be drawn in the morning?
Testosterone follows a pronounced circadian rhythm, peaking between 7:00 AM and 9:00 AM and dropping significantly by late afternoon. An afternoon blood draw can appear falsely low, leading to misdiagnosis of hypogonadism.
Related Laboratory Tests
Tests frequently prescribed together or used as follow-up investigations:
FSH, LH & Prolactin (Fertility & Pituitary Panel)
Anterior pituitary hormones governing ovarian follicle development, ovulation, and lactation.
PSA (Prostate-Specific Antigen — Total & Free)
Glycoprotein enzyme produced by prostatic epithelial cells circulating in free and protein-bound states.
Fasting Serum Insulin & HOMA-IR
Fasting blood insulin concentration and calculated mathematical Homeostatic Model Assessment of Insulin Resistance.
Medical & Diagnostic Disclaimer
This guide is published for educational and patient informational purposes only. It is not a substitute for professional medical evaluation, diagnosis, or clinical advice.
A laboratory result that falls slightly outside standard statistical reference intervals does not automatically indicate disease; conversely, a normal result does not guarantee the absence of medical conditions. Only your attending physician can interpret lab findings in the context of your medical history, physical exam, and symptoms.