Insight into your gamma-GT.
Gamma-GT is an enzyme that points mainly towards the bile ducts and responds sensitively to alcohol and certain medicines. It is often the first liver value to change.
Also known as: GGT, gamma-GT, gamma glutamyl transferase, bile ducts
Interpreted by BIG-registered doctors
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Background
What is gamma-GT?
Gamma-GT (gamma-glutamyl transferase, abbreviated GGT) is an enzyme found in abundance in the cells that line the bile ducts. If the drainage of bile stagnates, or if the bile ducts become irritated, gamma-GT rises in the blood. It therefore complements the liver tests ALT and AST: those point mainly to irritation of the liver cells themselves, while gamma-GT points more towards bile drainage.
Gamma-GT is sensitive to alcohol and to certain medicines, and is therefore often the first value to respond. A rise does not automatically mean there is damage, but it does indicate that the liver is under load. Because gamma-GT is so sensitive, it is often read together with alkaline phosphatase: if both are raised, that more often points towards the bile ducts; if only gamma-GT is raised, alcohol or medicines often play a role.
In brief
Bile ducts
Points towards the drainage of bile
Sensitive to alcohol
Gamma-GT responds to alcohol and certain medicines
Responds early
Often the first liver value to change
Complements ALT/AST
Together they give a fuller liver picture
Common reasons to test
When can insight into your Gamma-GT be valuable?
Below are some situations in which measuring Gamma-GT can provide insight.
Insight into your bile duct values
Gamma-GT assesses the drainage of bile and complements the liver tests ALT and AST.
With regular alcohol use
Gamma-GT is sensitive to alcohol. Those who want to know what their use does to this value have gamma-GT measured.
With a raised liver value
If your ALT or AST is raised, gamma-GT helps determine whether the bile ducts also play a role.
With long-term medication use
Various medicines can raise gamma-GT. Insight into this value is then relevant.
Tracking a value over time
For gamma-GT the development over time is often more informative than a single measurement. Re-testing makes a change visible.
What your result means
How do we read your Gamma-GT level?
Gamma-GT is measured in units per litre (U/L). The laboratory states the reference values that apply there alongside your result. Important: alcohol, medication use and fatty liver can influence this value.
A low value
A low gamma-GT generally has no medical significance. Our doctor provides explanation and context with your result.
A normal value
A value within the laboratory's reference values gives a reassuring picture of bile drainage at this moment. It remains a snapshot. The doctor always assesses your value together with your symptoms and your other liver values.
An elevated value
A raised gamma-GT points to load or irritation of the bile ducts. Alcohol and certain medicines are common explanations; fatty liver can also play a role. If your alkaline phosphatase is raised as well, that more often points towards the bile ducts. A single measurement is not a diagnosis. Our doctor explains what your value means and whether re-testing or follow-up via your GP is customary.
How we interpret your result
Our doctors interpret your gamma-GT against the laboratory's reference values and your personal context, such as lifestyle, alcohol use, medication use and any known conditions.
Related tests
Often combined with Gamma-GT.
A single marker gives one perspective. For a broader picture you can combine Gamma-GT with a theme package or related markers.
Frequently asked questions
Everything you want to know
Do I need to fast for this test?
No, you do not need to fast for gamma-GT. If you are also measuring glucose or cholesterol at the same time, fasting is customary.
What is the difference between gamma-GT and ALT or AST?
ALT and AST are found mainly in the liver cells and rise with irritation or damage to those cells. Gamma-GT comes mainly from the cells around the bile ducts and points more towards the drainage of bile. They therefore complement each other.
Why is gamma-GT raised with alcohol use?
Gamma-GT responds sensitively to alcohol and to certain medicines. A rise does not automatically mean there is damage, but it does indicate that the liver is under load. The doctor takes this into account in the interpretation.
Which medicines influence gamma-GT?
Various medicines can raise gamma-GT, for example some anti-epileptics, painkillers and antibiotics. Supplements and herbal preparations can also play a role. Please mention your medication with your result, so the doctor can take it into account.
Can a single elevated value mean a bile duct problem?
No. A single measurement is not a diagnosis. The doctor looks at your gamma-GT together with your other liver values and your context, and advises whether re-testing or follow-up is useful. Gamma-GT is often read together with alkaline phosphatase.
How often should I have gamma-GT measured?
A single measurement is enough for initial insight. With a previously abnormal value or with a lifestyle change you want to follow, re-testing after a few months is customary.
What do I do with my result?
You receive a PDF report with your value and personal explanation. What you do with it, such as discussing it with your GP, remains entirely your choice.
Ready for insight into your gamma-GT?
For €54 you receive your gamma-GT including personal explanation from a doctor, typically within a few working days. No referral required.
Order Gamma-GT for €54 →Want to test multiple markers at once?
Combine Gamma-GT with other markers via Bloodworks Select. Blood draw costs are waived from €225.
54,-
All-in, blood draw included