Biomarker . Patient guide
GGT Blood Test
What is GGT
Gamma-glutamyl transferase (GGT) is a liver enzyme that is especially sensitive to alcohol and to problems with the bile ducts. It is often used alongside ALP to work out whether a raised enzyme is coming from the liver or from bone.
This biomarker entry is being clinically reviewed by our team. The factual content draws on UK guidance (NICE, NHS, Royal Colleges and the relevant speciality society where cited).
Reference range
Reported in U/L. Final reports always carry the issuing laboratory's range, which is what your clinician will interpret against.
| Group | Range | Note |
|---|---|---|
| Adult men | approx. 10 to 55 | U/L |
| Adult women | approx. 10 to 38 | U/L |
What it is
GGT is found in the cells lining the liver and bile ducts. It rises with cholestasis (impaired bile flow) and is induced by alcohol and certain medications, which is why it is one of the most sensitive, though not the most specific, markers of alcohol-related and bile-duct liver problems.
Why a clinician would order it
GGT is checked to investigate a raised ALP (a raised GGT confirms a liver rather than bone source), to support assessment of alcohol intake, and to investigate cholestasis (itching, pale stools, dark urine). It is frequently added when other liver enzymes are abnormal.
If your level is outside the range
Symptoms of low GGT
What low can indicate. A low GGT is not clinically significant.
Symptoms of high GGT
- Usually none
- With cholestasis: itching, jaundice, pale stools, dark urine
What high can indicate. Regular or heavy alcohol intake, fatty liver, bile-duct obstruction or gallstones, and enzyme-inducing medications. An isolated mildly raised GGT with otherwise normal liver tests is common and often relates to alcohol or fatty liver.
Testing tips
No fasting needed. GGT can stay raised for a few weeks after a period of drinking, so it reflects recent rather than just current intake.
Sources
UK guidance our clinicians use when interpreting this marker.
This page is general patient information, not personal medical advice. A GMC-registered clinician will review your results and tailor any interpretation to you. See our Editorial Policy for how we write and review content.
Common questions about GGT
What is a normal GGT range?
Adult men: approx. 10 to 55 (U/L). Adult women: approx. 10 to 38 (U/L). Always interpret your own results against the laboratory range printed on your report, since assay-specific reference ranges vary.
What does a low GGT result mean?
A low GGT is not clinically significant.
What does a high GGT result mean?
Regular or heavy alcohol intake, fatty liver, bile-duct obstruction or gallstones, and enzyme-inducing medications. An isolated mildly raised GGT with otherwise normal liver tests is common and often relates to alcohol or fatty liver.
Do I need to fast or prepare for the GGT blood test?
No fasting needed. GGT can stay raised for a few weeks after a period of drinking, so it reflects recent rather than just current intake.
Can I order a GGT blood test privately in London?
Yes. WMG Health offers GGT as part of bespoke panels and several pre-built panels at our 134 Harley Street clinic. Results are clinician-reviewed by a GMC-registered doctor within 4 hours for the most common assays. All panels are custom-built around your specific question; bookings via /contact/ or 020 3239 3378.