Gamma-Glutamyl Transferase (GGT)
GGT is strongly right-skewed and rises with age, particularly in men, reflecting alcohol exposure, metabolic liver disease, medication effects, and cholestatic processes across the population.
Unit: U/L · 12 groups · age and sex · 1 source
Filed under panels: Liver Function , Metabolic Panel · topics: Liver , Metabolic
Gamma-Glutamyl Transferase (GGT) by age and sex
| Age (years) | Males (U/L) | Females (U/L) |
|---|---|---|
| 20-29 | median 21 middle 90% 10 to 76.7 | median 14 middle 90% 7 to 45.5 |
| 30-39 | median 25.4 middle 90% 11.1 to 93.2 | median 15 middle 90% 7 to 44.6 |
| 40-49 | median 26 middle 90% 12 to 105.3 | median 15 middle 90% 7.3 to 57 |
| 50-59 | median 26 middle 90% 13 to 115.8 | median 20 middle 90% 9 to 74 |
| 60-69 | median 24 middle 90% 11.8 to 91.8 | median 18 middle 90% 9 to 64.9 |
| 70+ | median 22 middle 90% 10.1 to 81 | median 17 middle 90% 9 to 58.7 |
Download Gamma-Glutamyl Transferase (GGT) percentiles (CSV) Values at full stored precision; tables on this site may round for display. Licensed under CC BY 4.0.
Population Distribution
Gamma-glutamyl transferase (GGT) is a liver and biliary enzyme measured on the standard chemistry panel. It is highly sensitive to alcohol exposure, metabolic dysfunction, medication effects, and cholestatic disease, which gives the population distribution a pronounced right tail. These percentiles describe the full US population rather than a screened healthy subgroup, and the per-group pages break the distribution down by sex (men and women) and age.
Frequently Asked Questions
Why is GGT so right-skewed?
Most adults have modest GGT values, but alcohol use, steatotic liver disease, medication exposure, cholestasis, and chronic cardiometabolic disease push a smaller subgroup much higher. That creates a long upper tail.
Why is GGT usually higher in males?
At the population level, men have more of the exposures that shift GGT upward, especially alcohol-related and metabolic-liver contributors, so the whole distribution tends to sit higher than in women.
How is GGT used with ALP?
A high ALP with a high GGT points more strongly toward a hepatobiliary source. A high ALP with a normal GGT makes a bone source more plausible.
What is a normal GGT reference range for women?
There is no single value: among US women the median GGT runs from about 14 to 20 U/L across adult age groups, and the middle 90% of women fall between roughly 7-9 U/L and 50-75 U/L, with the upper end rising with age. These are population percentiles, not a clinical reference interval. See the per-age female pages for the exact range in each women's age group.
Data Sources
Cite this data
LabNorms. Gamma-Glutamyl Transferase (GGT) population percentiles by age and sex. Data: NHANES 2017-March 2020 Pre-Pandemic. https://labnorms.com/analytes/ggt/. Licensed under CC BY 4.0. Accessed [date].
Download Gamma-Glutamyl Transferase (GGT) percentiles (CSV) Values at full stored precision; tables on this site may round for display. Licensed under CC BY 4.0.