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Oxidative Stress Biomarker (Total Antioxidant Capacity) – Serum

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

This test measures the body’s natural ability to neutralize harmful free radicals, which can cause cell damage. It reflects overall oxidative stress levels in your blood.

Quick summary

["Assessing your body’s antioxidant defenses to identify potential oxidative stress or support overall health."]

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

Key facts at a glance

LOINC
10240-0
Short code
O2 Ct RV-sCnc
Synonyms
O2 Ct RV-sCnc
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

What Does This Test Measure?

Total antioxidant capacity (TAC) evaluates the combined effect of various antioxidants in your blood, including vitamins (like vitamin C and E), enzymes, and other molecules that protect cells from oxidative damage caused by free radicals. Free radicals are unstable molecules that can harm cells if their levels become too high.

Why Might You Need This Test?

Doctors may order this test to monitor conditions linked to oxidative stress, such as chronic inflammation, certain cancers, or metabolic disorders. It can also help assess general health, especially in individuals concerned about aging, cardiovascular health, or exposure to environmental toxins.

How Is the Test Performed?

A small blood sample is drawn from a vein in your arm. The sample is then analyzed in a lab to measure the total antioxidant capacity using a specialized method, often involving colorimetric techniques to detect antioxidant activity.

What Are Common Reasons for Testing?

Common reasons include evaluating oxidative stress in patients with chronic diseases, assessing antioxidant status in those undergoing certain treatments (e.g., chemotherapy), or monitoring long-term health in individuals with a history of oxidative damage.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Total Antioxidant Capacity (TAC)

Frequently asked questions

How does this test help doctors?
This test helps identify whether your body’s antioxidant defenses are adequate to counteract oxidative stress. Low levels may indicate a higher risk of cell damage, inflammation, or disease progression, prompting further evaluation or interventions to support antioxidant health.
What if my results are high?
High total antioxidant capacity may suggest strong natural defenses against oxidative stress, which could be beneficial for overall health. However, it’s not a standalone indicator of disease risk and should be interpreted alongside other health factors.
What if my results are low?
Low total antioxidant capacity might mean your body has less protection against oxidative damage. This could be a sign of underlying health concerns, such as chronic inflammation or metabolic issues, and may guide additional testing or lifestyle recommendations.
  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