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Total Testosterone (Serum)

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

This blood test measures the amount of total testosterone, a key male sex hormone, in your serum. Testosterone plays a role in muscle and bone development, sex drive, and overall health in both men and women.

Quick summary

["Understanding your testosterone levels helps assess hormone balance and potential health concerns."]

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

Key facts at a glance

LOINC
109236-0
Short code
Testost Msmt Sal
Synonyms
Testost Msmt Sal
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 Is This Test Done?

Your healthcare provider may order this test to evaluate symptoms such as low libido, fatigue, or changes in body hair. It can also be used to diagnose conditions like hypogonadism (low testosterone) or to monitor treatment for hormone-related disorders.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the blood draw if your test is part of a broader hormone panel. Avoid heavy exercise or smoking for 24 hours prior.

What Happens During the Test?

A healthcare professional will draw blood from a vein in your arm. The sample is sent to a lab for analysis using an immunoassay method to measure testosterone levels.

What Are the Results?

Results are typically reported as a concentration value (in nanograms per deciliter, ng/dL, or other units). Your provider will compare these results to your individual reference range and clinical picture.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Total Testosterone

Frequently asked questions

What causes abnormal testosterone levels?
Abnormal testosterone levels can result from hormonal imbalances, medical conditions (e.g., thyroid disorders, kidney disease), medications, or lifestyle factors (e.g., obesity, smoking). Chronic stress or sleep deprivation may also affect hormone production.
How long does it take to get results?
Testosterone results are usually available within 1–3 business days, depending on your lab’s processing time. Follow-up with your provider to discuss findings and next steps.
Can diet or supplements affect testosterone levels?
Yes, certain foods (e.g., zinc-rich foods, healthy fats), vitamins (like vitamin D), and supplements (e.g., ashwagandha) may influence testosterone. Avoid alcohol and excessive caffeine before testing, as they can temporarily alter hormone levels.
  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