What It Measures
The GGT test measures the level of gamma-glutamyl transferase enzyme in the blood. This enzyme is involved in the transfer of amino acids across cell membranes and in glutathione metabolism. Because GGT is highly concentrated in liver cells and bile duct cells, elevated levels typically reflect liver or biliary system stress, including from alcohol use, medications, or disease.
Gamma-Glutamyl Transferase (GGT) is an enzyme found primarily in the liver, bile ducts, and kidneys that plays a key role in glutathione metabolism and amino acid transport. It is a sensitive marker of liver and biliary dysfunction, oxidative stress, and alcohol consumption, and emerging research links elevated GGT to cardiovascular disease risk and all-cause mortality.
Current Value
What High Means
Elevated GGT can indicate liver disease (fatty liver, hepatitis, cirrhosis), bile duct obstruction, excessive alcohol consumption, medication-induced liver stress (e.g., from statins, acetaminophen, or anticonvulsants), pancreatitis, or congestive heart failure. High GGT is also strongly associated with oxidative stress, insulin resistance, metabolic syndrome, and increased cardiovascular disease risk. Persistently elevated GGT is an independent predictor of all-cause mortality in epidemiological studies.
Possible Symptoms
Often asymptomatic in mild elevations. With significantly elevated levels: fatigue, jaundice (yellowing of skin/eyes), dark urine, light-colored stools, abdominal pain or swelling (especially right upper quadrant), nausea, loss of appetite, unexplained itching (pruritus), and general malaise.
What Low Means
Low GGT levels are generally considered favorable and indicate good liver health and low oxidative stress. Very low levels are not typically clinically concerning. Rarely, extremely low GGT can be seen in hypothyroidism or certain genetic conditions affecting glutathione metabolism, but this is uncommon.
Possible Symptoms
Low GGT is typically asymptomatic and considered a sign of good health. No clinically significant symptoms are associated with low GGT levels.
Risk Factors
Non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease, metabolic syndrome, type 2 diabetes, cardiovascular disease, obesity, bile duct obstruction, hepatitis (viral or autoimmune), pancreatitis, certain medications (statins, NSAIDs, anticonvulsants, acetaminophen), congestive heart failure, and increased all-cause mortality risk.
Actionable Advice
Supplements
- •N-Acetyl Cysteine (NAC)
- •Milk Thistle (Silymarin)
- •Alpha-Lipoic Acid
- •Vitamin C
- •Vitamin E
- •Omega-3 Fatty Acids
- •Magnesium
- •Curcumin (Turmeric)
- •B-Complex Vitamins
- •Selenium
Diet & Lifestyle
- •Limit or eliminate alcohol consumption — alcohol is a primary driver of elevated GGT
- •Maintain a healthy weight — obesity and visceral fat strongly correlate with elevated GGT
- •Exercise regularly (150+ min/week moderate activity) — shown to reduce GGT levels
- •Eat a Mediterranean-style diet rich in vegetables, fruits, healthy fats, and lean protein
- •Minimize processed foods, refined sugars, and seed oils to reduce liver burden
- •Avoid unnecessary medications that stress the liver (e.g., excessive acetaminophen)
- •Manage blood sugar and insulin levels — insulin resistance drives GGT elevation
- •Stay well hydrated to support liver detoxification
- •Get adequate sleep (7-9 hours) to support liver regeneration
- •Consider intermittent fasting, which may improve liver enzyme levels
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Historical Trend
Related Biomarkers
Resources & Studies
All Readings
| Date | Value | Change |
|---|---|---|
| 2026-01-28 | 22 U/L | 0.0 |
| 2025-08-25 | 22 U/L | — |