GGT is a liver enzyme that's particularly sensitive to alcohol use and bile duct problems. It's often elevated before other liver enzymes and can help determine the cause of elevated ALP (alkaline phosphatase).
Gamma-Glutamyl Transferase (GGT) is an enzyme found mainly in the liver, with smaller amounts in the kidneys, pancreas, and intestines. GGT helps transport amino acids across cell membranes and plays a role in glutathione metabolism - your body's master antioxidant.
What makes GGT unique among liver enzymes:
- It's extremely sensitive to alcohol consumption - even moderate drinking can elevate GGT
- It rises in bile duct obstruction and can help distinguish liver vs bone causes of elevated ALP
- It can be elevated before other liver enzymes become abnormal
- It's a marker of oxidative stress and has been linked to cardiovascular disease risk
GGT is often included in liver panels or ordered as a follow-up to abnormal liver function tests, particularly when elevated ALP needs clarification or alcohol use is suspected.
Price
$5
Results
1 days
Lab Network
Quest
Fasting
Not Required
What's Measured
What This Test Measures
This test measures the level of GGT enzyme in your blood, reported in U/L. Normal GGT is typically 9-48 U/L for adults, though men tend to have higher levels than women. Values can increase with age and body mass.
Who Should Consider This Test
People with elevated ALP needing clarification (liver vs bone source), those with suspected alcohol-related liver problems, patients with bile duct symptoms, anyone with other abnormal liver enzymes, and people monitoring liver health with medication use.
Health Insights
Conditions Screened
Related Symptoms
When to Get Tested
No fasting required. For the most accurate results, avoid alcohol for at least 24 hours before testing. GGT is best interpreted alongside other liver enzymes like AST, ALT, and ALP.
Understanding Your Results
Normal GGT is typically 9-48 U/L. Mild elevations (2-3x normal) can occur with moderate alcohol use, medications, or fatty liver. Moderate elevations (3-10x) suggest liver disease or bile duct problems. Very high elevations (>10x) often indicate bile duct obstruction or severe liver disease.
What to Expect
After placing your order, you'll receive an email from Rupa Health (our lab order partner) within 24 business hours to sign a consent form and schedule your blood draw at a Quest Diagnostics location.
The blood draw typically takes just a few minutes. Results are usually available within 1 business days and will appear in your secure Justlabs dashboard.
Our results include reference ranges and easy-to-understand indicators showing whether your values are within normal limits.
Frequently Asked Questions
$5
Typical hospital cash price: $120–$200
+ $28 in standard lab & physician fees at checkout (no additional bills later)
$18 lab collection + $10 physician order
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