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Gamma-Glutamyl Transferase (GGT)

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Also known as: Gamma-Glutamyl Transpeptidase; GGTP; Gamma-GT; GTP
Formal name: Gamma-Glutamyl Transferase
Related tests: AST; ALT; ALP; Bilirubin; Liver Panel ; Ethanol

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At a Glance

Why Get Tested?

To evaluate for a possible liver disease or bile duct disease or to differentiate between liver and bone disease as a cause of elevated alkaline phosphatase (ALP); sometimes to screen for or monitor alcohol abuse

When to Get Tested?

When you have symptoms of a liver or bile duct disorder or as follow up when you have an increased ALP level

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?

GGT levels fall after meals; you may be instructed to fast (nothing to eat or drink except water) for at least 8 hours prior to the test. You may also be asked to stop drinking alcohol or taking certain prescription medications.