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Gamma-Glutamyl Transferase (GGT) in Serum or 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 to evaluate liver function and detect potential liver damage.

Quick summary

["GGT helps identify liver issues and assess how well your liver is functioning."]

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

Key facts at a glance

LOINC
13615-0
Short code
GABA CSF-mCnc
Synonyms
GABA CSF-mCnc
Category
chemistry
Sample
csf
Container
Sterile tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
1-2 mL
Stability
Immediate analysis required, Refrigerated: 1h
Hemolysis max
200
TAT
4–24 hours
Order
routine

What Is GGT Used For?

GGT is commonly used to diagnose and monitor liver conditions, such as alcohol-related liver disease, hepatitis, or bile duct blockages. It can also help determine if certain medications or toxins are affecting your liver.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The blood is then processed to separate the serum or plasma, where the enzyme activity is measured using a specialized lab test.

What Are Common Causes of Abnormal Results?

Elevated GGT levels may be linked to liver problems, heavy alcohol use, certain medications, or metabolic conditions. Lower-than-normal levels are less common but can sometimes occur with certain genetic disorders or liver disease.

When Might You Need This Test?

Your doctor may order a GGT test if you have symptoms like fatigue, jaundice, abdominal pain, or if you’ve been exposed to risk factors like heavy alcohol use, hepatitis, or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: GGT plays a key role in liver health monitoring. While it’s not always the first test for liver issues, it helps confirm or guide further evaluation when other tests suggest liver involvement. Persistently high levels may require additional testing or lifestyle changes.

Short name

GGT

Frequently asked questions

Why might my GGT test result be higher than expected?
Higher-than-normal GGT levels can result from liver disease, heavy alcohol consumption, certain medications, or metabolic conditions. Your doctor may recommend further testing or adjustments to your treatment plan.
Can diet or lifestyle changes affect GGT levels?
Yes, factors like alcohol consumption, certain medications, and liver-related conditions can influence GGT levels. Avoiding alcohol and discussing medications with your doctor can help provide clearer results.
What if my GGT test is normal but I still feel unwell?
A normal GGT result doesn’t rule out liver issues entirely. If you have ongoing symptoms, your doctor may order additional tests or evaluations to investigate further, such as liver enzymes, imaging, or a biopsy.
  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