GGT Test
This page explains the ggt test, what it measures, and how to arrange it. The GGT test measures gamma-glutamyl transferase, an enzyme found mainly in the liver. It is often ordered to check for liver or bile duct problems, especially when other liver tests are abnormal or when alcohol use is a concern.
- Sample type
- blood
- Category
- Liver
- Turnaround
- 1-3 business days
- Price
- $25
- Referral
- Not required
The GGT test measures gamma-glutamyl transferase, an enzyme found mainly in the liver. It is often ordered to check for liver or bile duct problems, especially when other liver tests are abnormal or when alcohol use is a concern.
What it measures
- Gamma-glutamyl transferase (GGT) — The main enzyme measured; higher levels can suggest liver or bile duct irritation.
- Total bilirubin — A yellow pigment from red blood cells; may be included to assess liver function.
- Alkaline phosphatase (ALP) — Another enzyme that can rise with bile duct blockage.
- ALT and AST — Liver enzymes that help show if liver cells are inflamed or damaged.
Who it is for
A doctor may order a GGT test if you have symptoms like jaundice, belly pain, or fatigue, or if you have a condition that affects the liver. It is also used to monitor people taking certain medicines or with known liver disease.
Preparation
No fasting is usually required for a GGT test. Tell your doctor about all medicines, supplements, and alcohol use, as these can affect results.
Results and what they mean
Results are reported as a number in units per liter (U/L), along with a reference range from the lab. A clinician interprets your GGT level in the context of your health, other tests, and medicines. This is general information, not medical advice; talk to your healthcare provider about what your results mean.
How to order this test
- Choose the test and place a confidential order online.
- Select a certified collection site and pick a time that suits you.
- Have your specimen collected — most draws take only a few minutes.
- Review results in a secure portal, typically within 1–3 days.
Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.
Availability by state
Direct-access online ordering for the ggt test is available in most states. It is currently unavailable in 6 states:
Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →
Frequently asked questions
Do I need to fast for a GGT test?
No, fasting is not typically required. You can eat and drink normally unless your doctor gives other instructions.
What can cause a high GGT?
Many things can raise GGT, including alcohol use, liver disease, bile duct problems, and some medicines. A single high result does not diagnose a specific condition.
Can I drink alcohol before the test?
Alcohol can affect GGT levels. It is best to avoid alcohol for at least 24 hours before the test, or as advised by your doctor.
Is this test confidential?
Yes, your test results are protected health information and are kept private by your healthcare provider and lab.