Gamma-glutamyl transferase: liver enzyme sensitive to alcohol, drugs, and bile-duct stress.
What it is
GGT is reported in U/L and often rises with enzyme-inducing drugs, alcohol use, and cholestasis. Useful alongside ALP when exploring a biliary pattern.
Gamma-glutamyl transferase is abundant in liver and bile ducts. It is inducible by alcohol and several drugs, and rises with cholestasis. Reported in U/L.
Why it matters
Isolated GGT rises are common and non-specific. Marked rises with ALP/bilirubin changes need clinical assessment. Be honest with clinicians about alcohol, it materially changes interpretation.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
How it affects the body
GGT participates in glutathione metabolism and is enriched in biliary epithelium; induction and cholestasis both elevate blood levels.
GGT helps transfer amino acids and maintain intracellular glutathione. Induction of microsomal enzymes and impaired bile flow both spill GGT into plasma.
For athletes
Athletes cutting weight or socialising in season should still treat rising GGT as a health signal, not a badge of training stress.
A raised GGT in an athlete is a prompt for honest alcohol and medicine review, not an excuse to add another recovery supplement. Pair with ALT/AST/ALP for pattern recognition under clinical care.
