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Gamma-glutamyl transferase (GGT) in serum/plasma

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

This test measures the activity of an enzyme called gamma-glutamyl transferase, which helps break down certain amino acids. It’s often checked alongside other liver function tests.

Quick summary

["GGT can indicate liver health and exposure to certain substances."]

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

Key facts at a glance

LOINC
93425-7
Short code
GABABR IgG Titr CSF IF
Synonyms
GABABR IgG Titr CSF IF
Category
coagulation
Sample
csf
Container
Sterile tube
Units
N/A
Ref low
8
Ref high
61
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
CPT
82977
SNOMED
3110003
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

What Does This Test Measure?

Gamma-glutamyl transferase (GGT) is an enzyme found in the liver, bile ducts, and other organs. It plays a role in the metabolism of amino acids and detoxification processes. Elevated levels may suggest liver damage, alcohol use, or exposure to toxins.

Why Might Your Doctor Order This Test?

Doctors may request GGT testing to evaluate liver function, diagnose conditions like alcohol-related liver disease, detect bile duct blockages, or monitor treatment for conditions such as hepatitis or cirrhosis.

Common Causes of Abnormal Results

High GGT levels can be linked to liver diseases (e.g., hepatitis, cirrhosis), alcohol consumption, certain medications, or metabolic disorders. Low levels are less commonly significant but may occur in rare cases of liver dysfunction.

What to Expect During the Test

A blood sample is drawn from a vein, usually in your arm. You may feel a slight pinch, but it’s quick and painless. No special preparation is needed unless instructed otherwise by your healthcare provider.

Reference range

Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A

Specimen: csf

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Serum/plasma GGT

Frequently asked questions

How often should I get this test?
Your doctor will determine the frequency based on your health history, symptoms, and other test results. Regular monitoring may be recommended if you have liver-related conditions or risk factors.
Can lifestyle changes affect GGT levels?
Yes, reducing alcohol intake, avoiding certain medications, and maintaining a healthy diet can help lower GGT levels if they are elevated. Always discuss lifestyle changes with your healthcare provider.
What if my results are outside the normal range?
If your results are abnormal, your doctor will review them with you and may recommend further testing or adjustments to your treatment plan. Follow-up care depends on your specific situation.
  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