What is Gamma GT?

The liver plays a central role in your health – it filters toxins, processes nutrients, and supports metabolism. An important blood value for assessing liver function is Gamma-GT (gamma-glutamyltransferase). If this value is elevated, it may indicate liver damage or other conditions. In this article, you will learn what Gamma-GT is, which values are considered normal, why this marker is important, and what you can do if your levels are elevated.

Table of Contents

• What is Gamma GT?
• Gamma GT values
• The causes of an elevated Gamma GT value
• Are there any diseases related to Gamma GT?
• What happens if my Gamma GT is too high?
• How do I lower my Gamma GT level?

What is Gamma GT?

Gamma-GT (gamma-glutamyltransferase, GGT) is an enzyme that is frequently measured in blood tests to assess liver health. It plays a role in protein and glutathione metabolism and is present in small amounts throughout the body – with the highest concentrations found in the liver. When the liver is damaged or under strain, more gamma-GT can enter the bloodstream. For this reason, gamma-GT is considered an important marker in liver function tests. Together with other values such as ALAT, ASAT, and AP, the gamma-GT level provides insight into how well your liver is functioning (Cleveland Clinic, 2024).

Why is Gamma GT important?

Gamma-GT is produced in the liver and is involved in the breakdown and transport of amino acids. When the liver is impaired, the Gamma-GT level in the blood can rise.
Usually, Gamma-GT is measured together with other liver values to obtain a comprehensive picture of liver health. Elevated values alone are nonspecific and must always be interpreted in context.
Severe liver damage can lead to significant health problems, up to and including the need for a liver transplant.

Gamma GT values

The reference ranges differ according to age and sex and may vary depending on the laboratory.

Important: The exact reference values depend on the laboratory, the testing method, and individual factors such as age, sex, or pregnancy.

What does an elevated Gamma-GT level mean?

An elevated Gamma-GT level is defined as exceeding the age- and sex-specific reference values.

• Men: > 66 U/L

• Women: > 39 U/L

A slightly elevated value does not automatically indicate liver damage – it may also be influenced by lifestyle factors or medications. Therefore, further testing and medical evaluation are required (Mayo Clinic, 2025).

The causes of an elevated Gamma GT value

A significantly elevated Gamma-GT level often points to a disease of the liver or bile ducts. Slightly elevated values can have a variety of causes, including:

• Regular or excessive alcohol consumption

• Certain medications

• Obesity and fatty liver disease

• Older age

• Diabetes mellitus

• Cardiovascular diseases (e.g., heart attack, stroke) – often due to shared risk factors

• Epilepsy or the use of certain antiepileptic drugs

The most common causes are alcohol-related liver damage and fatty liver disease (Maag Lever Darm Stichting, 2013).

Are there any diseases related to Gamma GT?

Several conditions can be linked to elevated Gamma-GT levels, including:

• Fatty liver (alcoholic or non-alcoholic)

• Liver cirrhosis (often due to long-term alcohol abuse)

• Bile duct narrowing or inflammation

• Diabetes mellitus

• Cardiovascular diseases

• Epilepsy

What happens if my Gamma GT is too high?

Elevated Gamma-GT levels often cause no symptoms, especially in the early stages of liver disease. Complaints usually appear only in more advanced stages of damage, such as:

• General weakness

• Fatigue

• Loss of appetite

• Nausea and abdominal pain

• Yellowing of the skin or eyes (jaundice)

How do I lower my Gamma GT level?

Reducing an elevated Gamma-GT level depends on the underlying cause:

• Alcohol abstinence: In cases of regular alcohol consumption, levels often decrease noticeably after just a few weeks of abstinence.

• Healthy lifestyle: A balanced diet, exercise, and weight reduction can normalize values – especially in the case of fatty liver.

• Review medications: Some medications increase Gamma-GT; talk to your doctor about possible alternatives.

• Treat underlying conditions: For illnesses such as diabetes or epilepsy, medical management is essential.

In many cases, levels improve after a few months of healthy lifestyle changes. However, whether and how quickly they normalize depends on the individual cause.

When should you see a doctor?

• If your Gamma-GT level is significantly or repeatedly elevated

• If other liver values (ALAT, ASAT, AP, bilirubin) are abnormal

• If you have symptoms such as jaundice, severe fatigue, or abdominal pain

Only a medical examination can determine whether an underlying disease is present and what treatment is necessary.

Testing Gamma-GT 

With the Homed-IQ liver function tests, you can easily check your Gamma-GT levels from home. A small finger prick is all that’s needed.

• Your sample is analyzed in a certified laboratory

• You receive your results discreetly and within a few days

• Additional liver values are measured, giving you a comprehensive picture of your liver health