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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 helps doctors assess liver health and detect possible liver damage or bile duct issues."]

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

Key facts at a glance

LOINC
26594-2
Short code
GABA CSF-sCnc
Synonyms
GABA CSF-sCnc
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

Why GGT Matters in Liver Health

Gamma-glutamyl transferase (GGT) is an enzyme found in high levels in the liver, bile ducts, and other organs. When your liver is inflamed, damaged, or blocked (e.g., by alcohol, infections, or gallstones), GGT levels can rise. This test helps identify early signs of liver problems, even before other symptoms appear.

Common Causes of Elevated GGT

High GGT levels may signal conditions like heavy alcohol use, certain medications (e.g., antibiotics, painkillers), fatty liver disease, or bile duct blockages. Low GGT is less common but could indicate liver disease in some cases.

When You Might Need This Test

Your doctor may order a GGT test if you have symptoms like jaundice (yellow skin), fatigue, abdominal pain, or if they suspect liver damage from alcohol, infections, or other conditions. It’s also sometimes checked as part of routine health screenings or before certain treatments.

What to Expect During the Test

A blood sample is drawn from a vein in your arm, usually in a doctor’s office or lab. The process is quick and rarely causes discomfort. No special preparation is needed unless your doctor instructs otherwise.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

GGT

Frequently asked questions

Could my GGT levels be affected by what I eat or drink?
Yes, certain foods and substances can influence GGT levels. Alcohol is the most well-known trigger—chronic use can significantly raise GGT. Some medications (like acetaminophen or statins) may also affect results. If you’re unsure, discuss your diet and medications with your doctor before or after the test.
Why might my GGT be higher than normal, even if I don’t have obvious liver issues?
Elevated GGT can occur without clear symptoms in some cases, especially if the liver damage is mild or gradual. Other factors like obesity, certain infections, or genetic conditions may also play a role. Your doctor will review your medical history and other test results to understand the cause.
Is there anything I can do to lower my GGT levels if they’re high?
If your GGT is elevated due to lifestyle factors (like alcohol use or poor diet), lifestyle changes such as reducing alcohol, eating a balanced diet, and staying hydrated may help. Follow your doctor’s advice for personalized guidance, as treatment depends on the underlying cause.
  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