Liver function
GGT blood test
A GGT (gamma-glutamyl transferase) blood test measures a liver enzyme that is especially sensitive to the bile ducts, alcohol and certain medicines. It's part of a liver panel and is particularly useful for interpreting a raised ALP: a high GGT points to a liver rather than a bone cause.
- What it measures
- Gamma-glutamyl transferase, a liver enzyme
- Sample
- Venous blood sample
- Fasting
- Not required
- Also known as
- gamma-glutamyl transferase, gamma GT
- Included in 57 Health tests
- 8 panels, from £95
GGT reference range
Guide only| Category | Guide range |
|---|---|
| Adults (guide) | 10–70 U/L |
GGT tends to be higher in men, and ranges vary by laboratory. It's very sensitive to alcohol and some medicines, and is used alongside ALP: a raised ALP with a raised GGT suggests a liver cause, whereas a raised ALP with a normal GGT suggests a bone cause.
These are general UK adult guide ranges from public health sources, shown for orientation only. Reference ranges vary by laboratory, assay, age and sex, so your result is always interpreted against the range quoted by the analysing laboratory on your report.
What does a high GGT level mean?
A high GGT usually reflects the liver or bile ducts and is a sensitive marker of alcohol intake and of a number of medicines. It also rises with fatty liver disease and bile-flow problems.
Because GGT is sensitive but not specific, a raised result is interpreted alongside the rest of the liver panel and your history rather than on its own.
What does a low GGT level mean?
A low GGT is not a concern and needs no action.
A low or normal GGT is actually helpful information: with a raised ALP, it points the cause towards bone rather than the liver.
When to consider a GGT test
- A general or liver health check
- Making sense of a raised ALP (liver vs bone)
- Reviewing alcohol intake and liver health
- Monitoring the liver while on certain medicines
- Symptoms such as fatigue, nausea or upper-abdominal discomfort
Frequently asked questions
This page is general information about a blood marker and is not medical advice or a diagnosis. A GGT test screens and gives context; results are interpreted by a clinician alongside your symptoms, history and other markers. Always follow the guidance on your own report.