A patient seated in the chair before a blood draw
In person

GGT

A liver enzyme sensitive to bile flow, measured from one draw.

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  • 2,000+ lab locations. Find one near you
  • Nothing due at the lab. FSA / HSA accepted
  • Ordered by a licensed clinician

At a glance

Collection
Blood draw
A standard blood draw at the lab.
Preparation
None
Nothing to do ahead of time. Water is fine.
Results
1 to 2 days
Typical turnaround after your visit.
Where
2,000+ lab locations
Nationwide, with nothing due at the lab.

About this test

GGT (gamma-glutamyl transferase) is an enzyme found mainly in the liver and bile ducts. It can rise when bile flow is affected or the liver is under stress, and alcohol can raise it. GGT stays in range in bone conditions, so it helps sort out a high ALP. No fasting is needed.

For adults 18 and older. Test availability varies by lab location.

Who should take this test?

People often add GGT after a high ALP or a past GGT result, or as part of routine liver blood work, and then go over the results with a healthcare provider.

Ask about this test

Not sure this is the right test?

AI-generated. For information only, not medical advice. Call 911 for an emergency.

What does this test measure?

Your result shows how much GGT is in your blood, which can help a healthcare provider understand a high ALP or another liver result and decide what to look at next.

Gamma-glutamyl transferase (GGT)
GGT is an enzyme found mainly in your liver and bile ducts. It can rise with many kinds of liver or bile duct stress, including the effects of alcohol and some medicines. Because GGT stays steady in bone conditions, it can help a provider tell whether a raised ALP comes from the liver.
Why it’s measured: Helps show whether a raised ALP is coming from the liver or bile ducts rather than bone.

How it works

  1. Step 1

    Order online

    Check out here. A licensed clinician in your state reviews your order and sends it to the lab.

  2. Step 2

    Visit a lab

    Bring a photo ID to any of 2,000+ lab locations. No fasting needed, and nothing is due at the lab.

  3. Step 3

    Get your results

    Results post to your account, usually in 1 to 2 days, each number next to the lab’s reference range.

Find a lab near you

Choose from 2,000+ lab locations nationwide. Your order works at any of them.

What your results tell you

GGT is reported as enzyme activity in units per liter (U/L) and shown next to the lab’s reference range for comparison.

  • Your number next to the lab’s reference range
  • Explained in plain language
  • A licensed clinician reviews your order and, if appropriate, orders the test.
  • A lab report you can download and share

A high GGT has several possible causes. A healthcare provider reads it with your other liver results and history to decide on next steps.

Clinical-grade testing, from the comfort of home.

From the lab to your report, every step of our process meets the gold standard in medical testing.

  • CLIA-certified labs

    Every lab we partner with is certified under the Clinical Laboratory Improvement Amendments, meeting both state and federal standards with regular independent inspections.

  • We protect your health data

    We protect your health data with encryption and do not sell it. Some results must be reported to public health authorities by law. See our Privacy Notice.

  • Rigorous quality assurance

    All partner labs run regular internal quality checks, participate in proficiency testing, and comply with federal and state lab regulations.

  • Clinician-reviewed reports

    Results are reviewed by an independent, licensed clinician.

Questions

Common questions.

Anything else, our care team answers by phone, text, or email.

ALP comes from both the liver and bone, so a high ALP alone doesn’t show which one is involved. GGT rises with many liver and bile duct problems but stays in range in bone conditions.

If ALP and GGT are both high, the liver is a more likely source. If ALP is high and GGT is not, bone may be the source.

It can. GGT is sensitive to alcohol, and it is used in looking at alcohol-⁠related liver disease. A high GGT on its own does not show how much someone drinks or whether the liver is damaged, so a healthcare provider reads it with other results.

GGT is a sensitive enzyme, which means it can rise for many reasons. It does not point to one cause, and it is not a direct measure of how well your liver works. A healthcare provider uses it with ALP, ALT, AST, and your history.

Lab tests are informational and don’t diagnose conditions on their own. Available to adults 18 and older; test availability varies by lab location. A licensed clinician reviews your order and, if appropriate, orders the test. All testing is performed at CLIA-certified laboratories. Not for emergencies: if you think you may be having a medical emergency, call 911.