GGT
An early-warning liver enzyme that often moves before ALT or AST.
What is it
GGT is an enzyme found in liver and bile duct cells. It is highly sensitive to bile flow problems, alcohol use, and certain medications.
Why it's measured
GGT has been studied as an early-warning marker for liver and metabolic issues, often rising before ALT or AST in research literature.
Reference range
Standard laboratory reference
< 50 U/L
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
Where does your number land?
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Drag to your own GGT (Gamma-Glutamyl Transferase) result.
Educational only, not a diagnosis. Ranges vary by laboratory. See which panel includes GGT (Gamma-Glutamyl Transferase).
What results may indicate
Elevated
Has been associated with alcohol use, fatty liver disease, bile duct issues, and metabolic syndrome in research literature.
Lower
Is generally considered favorable.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Part of comprehensive liver panels.
Related markers
Common questions
GGT is an enzyme found in liver and bile duct cells. It is highly sensitive to bile flow problems, alcohol use, and certain medications.
It's one of the markers used to build a fuller picture of your health. On its own it tells you very little, so it's most informative when reviewed alongside related markers.
It's measured from a standard blood draw at Quest or LabCorp. GGT (Gamma-Glutamyl Transferase) is one of the markers included in the OPTML Apex Panel, where your results are read across systems and reviewed by a U.S.-licensed physician.
Reference ranges vary by laboratory, and a single value rarely tells the whole story. Review your result with a physician in the context of your other markers, symptoms, and history.
GGT (Gamma-Glutamyl Transferase) is one signal among many. Answer a few quick questions and we’ll point you to the panel that fits.
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Find the right panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.
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