Educational information only. At Precursor, blood testing is requested and reviewed by a clinician and considered alongside your history and other markers, not as a stand-alone diagnosis. Testing is performed in NATA-accredited laboratories to ISO 15189 standards.

What is GGT?

GGT, or gamma-glutamyl transferase, is an enzyme found in the liver and bile ducts. It is particularly sensitive to the bile system and to certain external influences, which makes it a helpful supporting marker when interpreting the rest of a liver panel.

Why it matters

GGT rises with bile-duct issues and is also a well-known marker of alcohol intake and of some medications. When another liver enzyme called ALP is raised, GGT helps a clinician work out whether the source is the liver or the bones, making it a useful tie-breaker.

What your results can mean

Higher than optimal

A raised GGT can reflect alcohol, fatty liver, bile-duct issues or certain medications. It is interpreted alongside ALT, AST and ALP to understand the pattern.

Within the healthy range

A GGT in range is reassuring, and when ALP is raised, a normal GGT points the cause away from the liver and toward bone.

Reference ranges in Australia

GGT is reported in units per litre (U/L), with reference ranges that differ between men and women and between laboratories. Read your result against the range on your own report and alongside your other liver markers.

Test your liver with Precursor

GGT adds useful context to a liver panel. At Precursor it is measured as part of Full Advanced Bloods, a single clinician-reviewed blood draw covering your liver, heart, metabolic, hormonal, kidney, thyroid and nutrient markers together, giving you and your clinician a broad baseline to understand and track.