Home › Biomarkers › GGT
In an Austrian study of 163,944 adults, researchers looked at whether GGT is a risk factor for death from a disease of the heart and blood vessels.[1]
On this page you can read what gamma-GT is, what the guidelines say about a value that is too low or too high, what affects your value and which values are best to look at alongside it.
Also known as: gamma-glutamyltransferase, gamma-glutamyltranspeptidase, GGTP, GTP. At the lab: GGT.
GGT is an enzyme. An enzyme is a protein that speeds up certain chemical reactions in your body. Thousands of enzymes play a part in everything your body does.[2]
GGT is found throughout your body, but mainly in your liver. Your bile ducts are small tubes that carry bile into and out of your liver. Bile is a fluid your liver makes, and it is important for your digestion.[2]
A doctor may request the test if you have symptoms that could be linked to your liver. Think of tiredness, weakness, yellow skin and yellow eyes, loss of appetite, pain or swelling in your belly, nausea and vomiting, or a lot of itching.[2]
A high gamma-GT can be a sign of damage to your liver or your bile ducts. The test cannot tell you what the cause is. Usually, though, the higher the level, the more damage.[2]
GGT is usually measured together with or after other liver markers, often ALP. This helps your doctor see whether an abnormal result is more likely to come from your liver or from your bones.[2]
Drinking alcohol raises GGT. Most people who find it hard to keep their drinking under control have a high level. That is why the test is also used to monitor alcohol use.[2]
Researchers in Austria followed 163,944 adults to see whether GGT is linked to death from a disease of the heart and blood vessels. This shows that the marker also draws researchers' attention beyond the liver.[1]
Labplusarts, the lab BioProfile works with, uses a reference range of 0 to 55 u/l for GGT. The lab calls a level within those limits normal.[3]
| Value | What the lab says | Who it is for |
|---|---|---|
| 0 to 55 u/l[3] | Normal according to the lab | The lab does not name a separate group |
Source: Labplusarts, the lab BioProfile works with, reference range for GGT, list dated 24 September 2026.[3]
According to MedlinePlus, a low or normal GGT makes liver disease unlikely. If your ALP is high and your GGT is low or normal, that may point more towards a bone condition.[2]
According to MedlinePlus, a higher than normal GGT may point to damage to your liver. That damage can be linked to things such as inflammation of the liver, another liver condition, heavy drinking, inflammation of the pancreas, a blood sugar condition, a heart condition or a side effect of a medicine. The level does not tell you which cause it is. That is why your doctor also looks at your symptoms, your medical history and your other blood values.[2]
BioProfile is working on its own zones for each value, from risk to optimal. A doctor reviews those zones before they appear in your result.
Drinking alcohol raises GGT and can affect your result.[2]
Certain medicines and supplements can affect your result. Ask your healthcare provider whether there are any special instructions for the test.[2]
Smoking cigarettes can also affect your gamma-GT.[2]
GGT drops after a meal. Your healthcare provider may therefore ask you not to eat for a while before the test.[2]
GGT is included in BioProfile 77, 87, 121 and 150.[4]
The BioProfile editorial team wrote this page on 10 October 2026 from the sources below, which we read on 10 October 2026. Every number on this page appears in one of those sources, with that source's number next to it. An expert has yet to check this page; after that check, the expert's name and the date of the check will appear at the top. This page offers explanation, not a diagnosis. Discuss a value outside the range with your GP.
