GGT — Liver + Alcohol Marker
Gamma-glutamyl transferase is the most sensitive marker for alcohol-related liver stress — it rises before ALT/AST and falls within weeks of reducing intake. Optimal below 30 U/L.
Gamma-glutamyl transferase (GGT) is a sensitive liver enzyme that rises with alcohol intake, bile-duct stress, and fatty liver — and is the most reliable blood marker for detecting alcohol-related liver strain, complementing the standard ALT and AST. Optimal below 30 U/L; even borderline elevations warrant a lifestyle review.
The biomarker
- Name: GGT (Gamma-Glutamyl Transferase)
- Units: U/L
- Standard reference range: < 50 U/L (men); < 35 U/L (women)
- Optimal range: < 30 U/L
How to read your result
| Value (U/L) | Interpretation |
|---|---|
| < 30 | Optimal — no action |
| 30–50 | Borderline — review alcohol intake and fatty liver risk factors |
| 50–100 | Elevated — investigate further; repeat with ALT/AST |
| ≥ 100 | See a clinician — possible bile-duct disease, significant alcohol use, or liver pathology |
What moves the needle
- Alcohol. The single biggest lifestyle driver of elevated GGT in otherwise healthy adults — reduce intake and retest in 4 weeks to confirm the link.
- Diet. Reducing refined carbohydrates and added sugar lowers hepatic fat accumulation and, with it, GGT.
- Weight. 5–10% body-weight reduction commonly lowers GGT in people with non-alcoholic fatty liver.
- Clinician referral. If GGT remains above 100 after 4–8 weeks of lifestyle change, hepatology review is appropriate — persistent elevation can reflect bile-duct disease or other causes beyond diet and alcohol.
Why ask for it
- GGT is the most sensitive commonly available marker for alcohol-related liver stress — it rises before ALT and AST and falls within weeks of reducing alcohol intake, making it a useful before/after tracking tool.
- When GGT is elevated alongside normal ALT and AST, alcohol or bile-duct disease is more likely than hepatocellular injury — the combination narrows the differential.
- It is not always included on a basic metabolic panel; you may need to request it specifically.
Related protocols
- Magnesium RBC — Cellular Magnesium Status Explained
- ALT and AST — Liver Enzymes
- Zinc — Immune + Hormone Cofactor
Sources
AgeGen lab guides are educational only. We do not provide medical diagnosis, prescribe brands, or recommend specific doses. Talk to a licensed clinician before changing your supplement or medication routine.
