Testosterone, Total, Males (Adult), Immunoassay

Catalog information reviewed: August 24, 2026 by the Sunridge Medical clinical team.

What this laboratory test evaluates

DetailsTestosterone, Total, Males (Adult), Immunoassay – This test measures the level of testosterone in the body, which is mostly bound to transport proteins like sex hormone binding globulin (SHBG). Only a small fraction of testosterone is free and active. Understanding testosterone levels can help in diagnosing and treating conditions such as erectile dysfunction, infertility, gynecomastia (enlarged breast tissue in men), osteoporosis, and in assessing hormone replacement therapy.

What patients is this test right for?This test may be recommended for men showing symptoms of low testosterone levels or hormonal imbalance, including:

• Difficulty achieving or maintaining an erection
• Low sex drive
• Infertility
• Development of breast tissue
• Loss of bone mass (osteoporosis)
• Low energy levels and mood swings

What type of sample is required for this test?1 mL serum. A blood draw is necessary.

Test Resources • https://education.questdiagnostics.com/faq/FAQ202
• https://www.questdiagnostics.com/healthcare-professionals/clinical-education-center/faq/faq294
• http://education.questdiagnostics.com/faq/FAQ165

Additional test information

This test measures the level of testosterone in the body, which is mostly bound to transport proteins like sex hormone binding globulin (SHBG).

Collection and processing

• Sample type: Serum
• Fasting: No
• Estimated laboratory processing: Results should be available in 2 – 5 business days after the sample is collected

How Sunridge uses laboratory information

Sunridge considers the medical question, symptoms, history, medications, prior results, and whether the finding could change care before recommending testing. A laboratory result is not interpreted in isolation and does not establish a diagnosis by itself.

Before requesting this test

Availability, collection requirements, eligibility, and processing estimates can change. Sunridge reviews each request and, when appropriate, creates the order through Fullscript. Follow the current instructions supplied with the approved order.