Skip to content

Total Serum Testosterone

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

This test measures the amount of total 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 help determine reproductive health and overall well-being."]

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

Key facts at a glance

LOINC
41018-3
Short code
Testosterone.free+WB SerPl-sCnc
Synonyms
Testosterone.free+WB SerPl-sCnc
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
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?

Doctors may order a total testosterone test to diagnose or monitor conditions like low testosterone (hypogonadism), fertility issues, or symptoms of hormonal imbalances such as low energy, mood changes, or sexual dysfunction. It can also be part of routine health checks for men over 40 or those with risk factors like obesity or diabetes.

What Does the Test Involve?

You’ll provide a blood sample, usually drawn from your arm. The test measures the total testosterone concentration in your serum (liquid part of blood). Results are compared to general reference ranges, though individual needs may vary.

What Are Possible Results?

Results are not provided with specific numeric ranges here. Your doctor will interpret your results in relation to your symptoms, medical history, and other tests. Low or high levels may require further evaluation.

What Does It Mean to My Health?

Testosterone plays a role in many bodily functions. Low levels may cause fatigue, reduced libido, or muscle weakness, while high levels could indicate conditions like Cushing’s syndrome or tumors. Your doctor will discuss findings with you and recommend next steps if needed.

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.

◆Associated findings1

Short name

Total Testosterone

Frequently asked questions

How often will I need this test?
The frequency depends on your health status and doctor’s recommendations. Some people may need retests every few months, while others may only need it once.
What if my results are outside the normal range?
If your results are outside the expected range, your doctor will review them with you and may order additional tests or treatments to address potential issues.
Can lifestyle changes affect testosterone levels?
Yes, factors like diet, exercise, sleep, and stress can influence testosterone levels. Maintaining a healthy lifestyle may support balanced hormone function.
  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