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Total testosterone (serum/plasma mass concentration)

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

This test measures the total amount of testosterone, a key male sex hormone, in your blood. It helps assess hormone balance, especially in conditions affecting testosterone production or metabolism.

Quick summary

["Total testosterone levels can guide treatment for hormone-related health concerns."]

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

Key facts at a glance

LOINC
51005-7
Short code
Testosterone.free+WB SerPl HS-mCnc
Synonyms
Testosterone.free+WB SerPl HS-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
300
Ref high
1000
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
high-sensitivity
CPT
84403
SNOMED
33790003
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 like low libido, fatigue, or changes in body hair. It’s also used in diagnosing conditions such as hypogonadism (low testosterone), Cushing’s syndrome, or to monitor hormone therapy.

What to Expect Before the Test

No special preparation is needed, but avoid smoking or consuming alcohol for 24 hours before the draw. If you’re on medications (like steroids), let your provider know—some can affect testosterone levels.

How the Test Works

Blood is drawn from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed to measure testosterone concentration using a sensitive immunoassay method.

What the Results Mean

Results are compared to general reference ranges, but individual needs vary. Low levels may signal hormonal imbalances, while very high levels could indicate conditions like tumors or Cushing’s syndrome. Your provider will interpret results in context with your symptoms and medical history.

Reference range

Adult males: 300-1000 ng/dLN/A

Specimen: serum

For females: inform if menstrual cycle status. For certain tests, timing within menstrual cycle may matter.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: When This Test Matters

Short name

Total testosterone

Frequently asked questions

When might I need this test?
Your doctor may recommend it if you have symptoms like low energy, mood changes, or reproductive issues. It’s also part of routine checks for men over 40 or those with a family history of hormone disorders.
Could my results be affected by my diet or medications?
Yes—certain foods (like soy), supplements (e.g., zinc), or medications (e.g., steroids) can influence testosterone levels. Always disclose all medications and recent dietary changes to your provider.
What if my results are outside the normal range?
If your levels are low, your doctor may recommend further testing (like free testosterone or SHBG) or adjustments to your treatment plan. If high, additional tests (like cortisol or prolactin) may be needed to rule out underlying causes.
  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