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Testosterone, Serum (Total)

Published: August 9, 2026Updated: August 16, 2026

This test measures the total amount of testosterone, a key male sex hormone, in your blood. Testosterone helps regulate muscle and bone growth, sex drive, and red blood cell production.

Quick summary

["Your testosterone levels can affect energy, mood, and fertility."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
59990-2
Short code
Testost sp6 p chal SerPl-mCnc
Synonyms
Testost sp6 p chal SerPl-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Might You Need This Test?

Your doctor may order this test to evaluate symptoms like low libido, fatigue, or changes in body hair. It can also help diagnose conditions like hypogonadism (low testosterone) or assess hormone imbalances in both men and women.

What Does the Test Involve?

A blood sample is taken from a vein in your arm. The sample is sent to a lab for analysis using a sensitive immunoassay method to measure testosterone levels accurately.

What to Expect Before the Test

No special preparation is needed, but avoid heavy exercise or alcohol consumption 24 hours before the test if possible. If you’re on medications that affect hormones, let your doctor know.

What Are Common Reasons for Abnormal Results?

Low testosterone may indicate conditions like pituitary disorders, genetic disorders, or chronic illnesses. High levels could suggest tumors, Cushing’s syndrome, or other hormonal imbalances. Always discuss results with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Serum Testosterone

Frequently asked questions

How long does it take to get results back?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your doctor will contact you once they’re ready to review them.
Can I fast before this test?
No fasting is required for this test. However, if you’re concerned about how food or medications might affect your results, talk to your doctor beforehand.
Does this test show free testosterone or just total testosterone?
This test measures total testosterone, which includes both free (active) and bound (inactive) forms. Free testosterone is a smaller portion of the total, and your doctor may request a separate free testosterone test if needed.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy