GGT
Measures GGT, a liver and bile-duct enzyme. Often ordered when alkaline phosphatase is high to help separate liver sources from bone, or when alcohol-related liver stress is suspected.
GGT lives on the surfaces of liver cells and bile ducts and normally stays mostly inside tissue. When those tissues are irritated, blocked, or soaked in alcohol, the enzyme spills into the blood and the number climbs. Doctors reach for it when alkaline phosphatase is high and the question is whether the signal is coming from liver or bone, and when medication or drinking history makes bile-duct stress plausible. GGT is chatty, not specific: infection, stones, fatty liver, and dozens of drugs can nudge it. The pattern with ALT, AST, bilirubin, and your story matters more than one spike.
Self-Pay Price Comparison
| Provider | Price | vs. Highest | Order |
|---|---|---|---|
Quest QuestHealth self-pay | Not Available | N/A | Check Provider Site · Quest |
LabCorp Labcorp OnDemand | $59.00 | Highest | Order · LabCorp |
GoodLabs Discount lab network | $5.00Best value | Best price | Order · GoodLabs |
What This Test Measures
This order returns GGT as one enzyme activity line. Here is what that number reflects:
Enzyme concentrated in liver and bile duct tissue that leaks into blood when those tissues are irritated; high values often track with alcohol, medicines, or bile flow trouble, very low values are rarely actionable on their own.
How to Read Your Results
GGT is sensitive and loud about irritation, not specific about cause. Here is how clinicians usually triage the three common patterns:
| Marker | Normal Range | If Flagged | What It Might Mean |
|---|---|---|---|
| GGT (elevated) | Labs print their own U/L interval; MedlinePlus liver enzyme overviews note many benign causes before any single enzyme is called proof of one disease. | high | Alcohol, medicines, bile duct slowdown, and fatty liver are frequent drivers. Very high multiples of the upper limit get more urgent attention than a few points over. |
| GGT (normal with high ALP) | Quiet GGT while ALP climbs often steers the workup toward bone growth, healing fractures, or pregnancy rather than cholestasis. | low | Patterns beat singletons. Your doctor may still add imaging or fractionated ALP when the story does not fit. |
| GGT (mild bump after a celebration weekend) | Short-term alcohol exposure can raise GGT without chronic disease; repeat labs after a sober interval tell whether it stuck. | high | Transient bumps deserve honest timing. Blaming the lab without reviewing drinks and meds wastes a draw. |
When to Order
Elevated alkaline phosphatase without a clear source
GGT trending up with ALP points toward liver or bile ducts; GGT staying quiet leans the conversation toward bone or pregnancy-related ALP shifts.
Medication start or dose change
Many drugs irritate liver cells; GGT sometimes moves before ALT in mild injury patterns.
Heavy alcohol weeks before testing
GGT is sensitive to recent drinking; honesty about timing keeps the result interpretable.
Known fatty liver or hepatitis follow-up
Serial GGT with other liver enzymes shows whether lifestyle changes or treatment are bending the curve.
Yellowing skin or itchy skin with dark urine
Bile flow problems can lift GGT alongside bilirubin; imaging and other labs usually follow when symptoms match.
Prep & Logistics
- Fasting
- Typically no fasting
- Sample
- Blood draw
- Results
- Usually 24-48 hours; many portals update the same day or the next.
- Referral
- Often self-order (check local rules)
- Markers
- Single GGT activity reported in U/L (label varies by lab).
Tests That Pair With This One
ALT, AST, bilirubin, and ALP together when GGT moved and the liver panel is still incomplete.
Adds context when infection, hemolysis, or marrow issues sit in the same symptom window.
Metabolic risk overlay when fatty liver and cardiovascular prevention are the same conversation.
FAQ
GGT is high but ALT is normal—what does that mean?
GGT is sensitive to bile ducts, alcohol, and some drugs even when ALT is quiet. Your clinician reads it next to ALP, history, and meds—not as a single alarm.
I stopped drinking two days ago. Will GGT be normal?
Maybe not yet. GGT can lag weeks behind behavior. If the goal is a sober baseline, your doctor may wait and repeat rather than chase a single draw.
Is GGT the same as ALT?
Different enzymes from different angles. ALT is more tied to direct liver-cell injury in many textbooks; GGT adds bile-duct and alcohol sensitivity. Panels usually include both so the shape is visible.
Can exercise spike GGT?
Strenuous training sometimes nudges liver enzymes short term. Mention heavy workouts before the draw if your doctor is hunting a quiet baseline.
Sources
Prices pulled directly from provider websites and verified by hand. Reference context from MedlinePlus where linked. Not generated by AI.
- GoodLabs - product page (pricing context)(verified 2026-03-23)
- LabCorp OnDemand - GGT test (pricing context)(verified 2026-03-23)
- MedlinePlus - Liver Function Tests overview
- Clinical context: LabRecon editorial team. Not medical advice. For informational use only.
Gamma-glutamyl transferase is elevated in hepatobiliary disease, chronic alcohol use, and drug-induced liver injury. More sensitive than ALT for alcohol-related liver disease.