{"id":"ggt","name":"Gamma-Glutamyl Transferase (GGT)","shortName":"GGT","aliases":["Gamma-GT","GGT","GGTP","Gamma-Glutamyl Transferase","Gamma Glutamyl Transpeptidase","GGT, Serum","Gamma-Glutamyltransferase","y-Glutamyl Transferase","γ-GT","γ-Glutamyl Transferase (GGT)","Gamma-Glutamyl Transpeptidase","Gamma-Glutamyltranspeptidase","Gamma GT","Glutamyl Transpeptidase","Gamma Glutamyl Transferase, Serum or Plasma","Gamma-glutamyl transferase, serum"],"abbreviations":["GGT","GGTP","γ-GT","Gamma-GT"],"loinc":[{"code":"2324-2","primary":true}],"specimen":"serum-or-plasma","units":[{"ucum":"U/L","display":"U/L"},{"ucum":"ukat/L","display":"µkat/L"}],"referenceRanges":[{"population":"Men, 18+","low":0,"high":65,"unit":"U/L","unitDisplay":"U/L","note":"Labcorp prints 0–65 IU/L (the same number as U/L) for men and gives no age limits, so it is entered here for adults. Other published limits are lower. An IFCC-based study of hospital patients aged 17 and older put the 97.5th percentile at 55 U/L for men, Cleveland Clinic describes below about 50 U/L as typical, and a US NHANES III mortality study defined elevated GGT as above 51 U/L in men. Intervals differ by lab and method, so use the one printed on your own report first.","sources":[{"title":"γ-Glutamyl Transferase (GGT) (test 001958)","url":"https://www.labcorp.com/tests/001958/y-glutamyl-transferase-ggt","publisher":"Labcorp"},{"title":"Sample report, GGT (test 001958)","url":"https://files.labcorp.com/testmenu-d8/sample_reports/001958.pdf","publisher":"Labcorp"},{"title":"New IFCC reference procedures for the determination of catalytic activity concentrations of five enzymes in serum: preliminary upper reference limits obtained in hospitalized subjects","url":"https://pubmed.ncbi.nlm.nih.gov/12482620/","publisher":"Clinica Chimica Acta","year":2003},{"title":"Elevated serum alanine aminotransferase and gamma-glutamyltransferase and mortality in the United States population","url":"https://pubmed.ncbi.nlm.nih.gov/19100265/","publisher":"Gastroenterology","year":2009},{"title":"Gamma-Glutamyl Transferase (GGT) Blood Test","url":"https://my.clevelandclinic.org/health/diagnostics/22055-gamma-glutamyl-transferase-ggt-test","publisher":"Cleveland Clinic","year":2024}]},{"population":"Women, 18+","low":0,"high":60,"unit":"U/L","unitDisplay":"U/L","note":"Labcorp prints 0–60 IU/L (the same number as U/L) for women and gives no age limits, so it is entered here for adults. Other published limits are noticeably lower. An IFCC-based study of hospital patients aged 17 and older put the 97.5th percentile at 38 U/L for women, and a US NHANES III mortality study defined elevated GGT as above 33 U/L in women. Intervals differ by lab and method, so use the one printed on your own report first.","sources":[{"title":"γ-Glutamyl Transferase (GGT) (test 001958)","url":"https://www.labcorp.com/tests/001958/y-glutamyl-transferase-ggt","publisher":"Labcorp"},{"title":"New IFCC reference procedures for the determination of catalytic activity concentrations of five enzymes in serum: preliminary upper reference limits obtained in hospitalized subjects","url":"https://pubmed.ncbi.nlm.nih.gov/12482620/","publisher":"Clinica Chimica Acta","year":2003},{"title":"Elevated serum alanine aminotransferase and gamma-glutamyltransferase and mortality in the United States population","url":"https://pubmed.ncbi.nlm.nih.gov/19100265/","publisher":"Gastroenterology","year":2009},{"title":"Gamma-Glutamyl Transferase (GGT) Blood Test","url":"https://my.clevelandclinic.org/health/diagnostics/22055-gamma-glutamyl-transferase-ggt-test","publisher":"Cleveland Clinic","year":2024}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"A liver and bile duct enzyme. A higher level can be linked to alcohol, some medicines, fatty liver or bile duct problems.","url":"https://bloodtesttracker.com/markers/ggt","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}