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Serum or plasma concentration of gamma-glutamyltransferase (GGT)

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

Gamma-glutamyltransferase (GGT) is an enzyme that helps break down certain proteins. Your doctor may order this test to check for liver problems or other conditions affecting your liver or bile ducts.

Quick summary

["GGT helps detect liver damage or disease by measuring enzyme levels in your blood."]

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

Key facts at a glance

LOINC
59807-8
Short code
PG Amn-sCnc
Synonyms
PG Amn-sCnc
Category
glucose
Sample
fluid
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
2-5 mL
Stability
Room temperature: 2h, Refrigerated: 24h
Hemolysis max
300
TAT
4–24 hours
Order
routine

What Is GGT Used For?

GGT is often used to evaluate liver function, identify liver disease (such as hepatitis, cirrhosis, or fatty liver), or check for conditions that may affect bile flow, like gallstones or blockages. It can also help monitor treatment progress for certain liver-related conditions.

Common Causes of Elevated GGT Levels

High GGT levels may be linked to liver issues (e.g., alcohol use, infections, or inflammation), certain medications, or conditions like heart disease or diabetes. Low levels are less common but may occur with certain liver diseases or malnutrition.

How Is GGT Tested?

A blood sample is drawn, and the enzyme activity is measured using an immunoassay or enzymatic method. Results are reported as a concentration of the enzyme in your blood.

What Do GGT Results Mean?

Results alone don’t diagnose a condition—they’re usually reviewed alongside other tests and symptoms. Elevated GGT often signals potential liver stress, while normal levels don’t rule out liver disease entirely.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

GGT Level

Frequently asked questions

Why might my doctor order a GGT test?
Your doctor may recommend it if you have symptoms like fatigue, abdominal pain, or if they suspect liver issues (e.g., after drinking alcohol, taking certain medications, or having a viral infection).
What should I do if my GGT level is high?
Follow your doctor’s advice for lifestyle changes (like reducing alcohol or eating a balanced diet) and any prescribed treatments. Repeat testing may be needed to monitor progress.
Does diet affect GGT levels?
Yes—high-fat or heavy alcohol intake can raise GGT. Avoiding triggers and eating a liver-friendly diet may help lower levels over time.
  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