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Serum/plasma concentration of gamma-glutamyl transferase (GGT) measured by enzymatic method

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

This test measures the activity of an enzyme called gamma-glutamyl transferase (GGT), which helps assess liver function and detect potential liver damage or disease.

Quick summary

["GGT can signal liver issues, including alcohol-related damage or other conditions affecting bile flow."]

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

Key facts at a glance

LOINC
93427-3
Short code
GABABR IgG Titr SerPl IF
Synonyms
GABABR IgG Titr SerPl IF
Category
coagulation
Sample
serum
Container
Red-top tube (SST)
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
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

Why Is This Test Done?

Doctors may order a GGT test to investigate symptoms like jaundice (yellowing of skin/eyes), abdominal pain, fatigue, or unexplained liver enzyme elevations. It’s also used during liver disease evaluations, monitoring alcohol use, or checking for conditions like hepatitis or bile duct blockages.

What Does a High or Low GGT Level Mean?

Elevated GGT levels often point to liver problems, such as alcohol misuse, fatty liver disease, or bile duct issues. However, other factors like heart disease, heart failure, or certain medications can also influence results. Low GGT levels are less common but may occur in rare genetic conditions or during pregnancy.

How Is the Test Performed?

A blood sample is drawn from a vein in your arm. The sample is sent to a lab where the enzyme activity is measured using an enzymatic method, which detects how quickly a substrate is converted into a product over time.

What Should You Expect Before or After the Test?

No special preparation is usually needed, but avoid heavy alcohol consumption 48 hours before testing. Results may take a few days to weeks to receive, depending on lab processing times.

Reference range

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

Specimen: serum

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: GGT in Liver Health and Beyond

Short name

GGT Level

Frequently asked questions

What Are Common Causes of Abnormal GGT Levels?
Elevated GGT levels are frequently linked to liver diseases, including chronic alcohol use, hepatitis, or cirrhosis. It can also signal conditions like gallstones, non-alcoholic fatty liver disease, or certain medications that affect liver function. Rarely, GGT may be elevated in heart or muscle disorders.
How Often Should I Get This Test?
Your doctor will determine how often you need GGT testing based on your medical history, symptoms, and overall health. Regular monitoring may be recommended if you have a history of liver disease, alcohol use, or other risk factors.
Can GGT Levels Change Over Time?
Yes, GGT levels can fluctuate due to lifestyle factors (e.g., alcohol consumption), medications, or underlying health conditions. If your levels are abnormal, your doctor may recommend follow-up tests or adjustments to your treatment plan.
  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