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Testosterone, Serum or Plasma Mass Concentration

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

This test measures the amount of testosterone, a key male sex hormone, in your blood. It can help diagnose conditions related to hormone imbalances.

Quick summary

["Testosterone levels help assess hormone health and potential reproductive or metabolic issues."]

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

Key facts at a glance

LOINC
58835-0
Short code
Testost BS SerPl-mCnc
Synonyms
Testost BS 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 This Test Is Done

Your healthcare provider may order this test to evaluate symptoms such as low libido, infertility, irregular menstrual cycles, or signs of hormone-related conditions. It can also be used in fertility evaluations, before surgery (like prostate or breast cancer treatments), or to monitor hormone therapy.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the draw if your lab uses a specific method. Wear a loose shirt for easy access. Avoid smoking or caffeine right before the test.

What Happens During the Test

A healthcare professional will insert a needle into a vein in your arm to collect blood. You may feel a slight pinch, but the process is quick. The blood sample is sent to a lab for analysis.

What the Results Mean

Results are compared to general reference ranges, but individual needs vary. High or low levels may signal conditions like hypogonadism (low testosterone), Cushing’s syndrome, or polycystic ovary syndrome (PCOS). Your provider will interpret results in the context of your symptoms and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Testosterone levels are critical for muscle mass, bone density, mood, and sexual function. Abnormal results may indicate hormonal disorders, chronic illnesses, or side effects from medications. Regular monitoring is important for patients undergoing hormone replacement or managing conditions like diabetes or obesity.

Short name

Testosterone Level

Frequently asked questions

How is testosterone tested?
Testosterone is measured using a blood sample collected from a vein in your arm. The lab uses advanced techniques like immunoassay or mass spectrometry to detect and quantify the hormone in your serum or plasma.
What symptoms might lead to this test?
Common symptoms prompting this test include low energy, reduced sex drive, difficulty concentrating, unexplained weight changes, or signs of hormonal imbalances (e.g., breast tenderness in men). Your provider may also recommend it if you’re undergoing fertility treatment or before certain surgeries.
Can diet or exercise affect testosterone levels?
Yes. Healthy lifestyle choices—such as balanced nutrition, regular physical activity, and avoiding excessive alcohol—can support natural testosterone production. Stress, poor sleep, and certain medications may also influence results, so discuss these factors with your provider.
  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