About This Test

A testosterone test measures the level of testosterone in your blood. Testosterone is the primary male sex hormone, though it is also present in smaller amounts in females. Testing helps diagnose hormonal imbalances.

Types of Testosterone Tests

  • Total testosterone: Measures both bound and free testosterone
  • Free testosterone: Measures unbound, biologically active testosterone
  • Bioavailable testosterone: Free testosterone plus loosely bound

Normal Ranges (Males)

  • Adult males: 300-1,000 ng/dL (varies by age and lab)
  • Levels peak in early morning and decline throughout the day
  • Levels naturally decrease with age (about 1% per year after 30)

When Is Testing Recommended?

Males:

  • Erectile dysfunction or low libido
  • Infertility
  • Decreased muscle mass or strength
  • Fatigue or low energy
  • Depression or mood changes
  • Decreased body hair
  • Gynecomastia (breast tissue development)
  • Delayed or early puberty in boys

Females:

  • Excessive facial or body hair (hirsutism)
  • Irregular periods
  • Infertility
  • Acne
  • Male-pattern baldness
  • Polycystic ovary syndrome (PCOS) evaluation

Test Preparation

Test Preparation

Fasting: May be required; follow lab instructions.

Important Preparation Steps:

  • Time of day: Testosterone is highest in the morning (7-10 AM)
  • Multiple tests: Low results should be confirmed with repeat testing
  • Medications to report: Steroids, antifungals, antidepressants, hormones
  • Avoid: Biotin supplements (can affect results)

What to Expect:

  • Blood draw from arm
  • May need multiple samples at different times
  • Results in 1-3 days

Female Testing Considerations:

  • Best tested at specific points in menstrual cycle
  • Your doctor will provide timing instructions
  • May need additional hormone tests (DHEA, androstenedione)

Understanding Your Results

Understanding Results

Low Testosterone (Hypogonadism)

In Adult Males:
  • Below 300 ng/dL (varies by age and symptoms)
  • Requires confirmation with repeat morning test
Causes:
  • Primary hypogonadism (testicle problems)
  • Secondary hypogonadism (pituitary/hypothalamus problems)
  • Aging
  • Obesity
  • Chronic illness
  • Medications (opioids, steroids)
  • Sleep apnea
Symptoms:
  • Low sex drive
  • Erectile dysfunction
  • Fatigue
  • Depression
  • Decreased muscle mass
  • Increased body fat

High Testosterone

In Males:
  • Rare, but may indicate adrenal or testicular tumors
  • Anabolic steroid use
In Females:
  • Polycystic ovary syndrome (PCOS)
  • Adrenal disorders
  • Ovarian tumors

Treatment Considerations

Testosterone Replacement Therapy (TRT)

Forms:
  • Injections
  • Gels/patches
  • Pellets
  • Nasal gel
  • Buccal tablets
Risks:
  • Blood clots
  • Sleep apnea worsening
  • Prostate issues
  • Acne
  • Breast enlargement
  • Reduced fertility
Not recommended for:
  • Prostate or breast cancer
  • High red blood cell counts
  • Severe sleep apnea
  • Heart failure

Related Tests

  • Luteinizing hormone (LH)
  • Follicle stimulating hormone (FSH)
  • Prolactin
  • Estradiol
  • Sex hormone binding globulin (SHBG)
  • DHEA-S
  • PSA (if considering TRT)

Sources

Last Reviewed: April 2026