Testosterone

Test Overview

The Testosterone Test measures the levels of testosterone, a crucial hormone responsible for muscle mass, bone density, libido, mood regulation, and overall hormonal balance in both men and women. Testosterone is produced primarily in the testes (in males) and the ovaries and adrenal glands (in females). This test helps diagnose hormonal imbalances, infertility, sexual dysfunction, and other endocrine disorders.

Test Types

Total Testosterone – Measures both bound and unbound testosterone in the blood.
Free Testosterone – Measures the unbound, active form of testosterone.
Bioavailable Testosterone – Includes free testosterone and testosterone weakly bound to albumin, representing the most usable form.
SHBG (Sex Hormone-Binding Globulin) – Measures the protein that binds to testosterone and regulates its availability.

Testosterone Test Results & Ranges

Test Component:	Normal Range (Men):	Normal Range (Women):	Abnormal (Possible Conditions):
Total Testosterone	300–1,000 ng/dL	15–70 ng/dL	High: PCOS, tumors, steroid use Low: Hypogonadism, aging, pituitary disorders
Free Testosterone	5–25 ng/dL	0.1–2.2 ng/dL	High: Androgen excess, insulin resistance Low: Low libido, fatigue, erectile dysfunction
Bioavailable Testosterone	40–250 ng/dL	0.5–10 ng/dL	High: Tumors, excess androgen production Low: Low energy, muscle loss, hormonal imbalance
SHBG (Sex Hormone-Binding Globulin)	10–57 nmol/L	18–144 nmol/L	High: Liver disease, hyperthyroidism Low: Insulin resistance, obesity, hypothyroidism

Expected Turnaround Time

Results Available: 1–3 business days

Specimen Requirements

Sample Type: Blood sample (venipuncture)
Container: Serum separator tube (SST)

Collection Instructions

Best collected in the morning (7–10 AM) when testosterone levels are highest.
Fasting is not required, but some doctors recommend it for consistency.
Avoid strenuous exercise and alcohol 24 hours before testing, as they may temporarily affect levels.
Inform your healthcare provider if you are taking testosterone therapy, steroids, or other hormone-affecting medications.

Storage: Blood samples should be processed promptly and stored according to lab protocols, typically refrigerated or at room temperature until testing.

Test Details

Clinical Use:

Diagnoses low testosterone (hypogonadism) – Identifies low energy, low libido, erectile dysfunction, and muscle loss in men.
Evaluates androgen excess – Assesses conditions like polycystic ovary syndrome (PCOS) in women.
Monitors hormone therapy – Ensures proper dosing of testosterone replacement therapy (TRT).
Assesses fertility and reproductive health – Helps investigate infertility in both men and women.
Checks for metabolic and endocrine disorders – Evaluates conditions like pituitary dysfunction, insulin resistance, and adrenal gland disorders.

Limitations:

Testosterone levels fluctuate throughout the day, so multiple tests may be needed for accuracy.
Certain medications and medical conditions can affect testosterone levels.
A single low result does not confirm testosterone deficiency – additional hormone tests may be required.

The Testosterone Test is essential for assessing hormonal health, reproductive function, and overall well-being, helping with diagnosis, treatment, and long-term health management.