AI Summary The ethyl glucuronide (EtG) test checks urine or hair for a byproduct of alcohol. Urine detects drinking for up to 80 hours; hair covers up to six months. Doctors order it in alcohol-related liver disease to support staying alcohol-free, and cirrhosis does not affect urinary results. It shows alcohol was present, not how much. After a result, build a support plan, ask about medicine, and talk with your doctor before stopping alcohol.
Source: www.liverdirectory.com
Medically Reviewed.
Ethyl glucuronide (EtG) is a substance your body makes when it breaks down alcohol. Finding it in urine or hair shows that alcohol was in your body.
Liver doctors use the EtG test in alcohol-related liver disease, where staying completely alcohol-free is the most important step in treatment. A result supports your care. It is not a judgment.
Below, you will find key facts, how EtG compares with other markers, why doctors order it, what to expect, how to read a result, and answers to common questions.
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Alcohol biomarker basics
An EtG test measures ethyl glucuronide, a substance the body makes when it processes alcohol. The test can use a urine sample (urinary EtG, or uEtG) or a sample of scalp hair (hair EtG, or hEtG).
EtG is a direct marker of alcohol. It comes from the way the body handles alcohol itself. Indirect markers, such as the liver enzyme GGT and the red blood cell measure MCV, show how alcohol may be affecting the body. They are less specific to alcohol. EtG is highly specific, and urinary EtG is rated as superior to GGT and MCV.
The test matters most in alcohol-related liver disease (ARLD), also called alcohol-associated liver disease. Sustained abstinence is the cornerstone of treatment. An EtG result gives your care team an objective lab finding to go with what you tell them.
For the full group of alcohol markers, see Alcohol Biomarker Testing. For a blood-based option, see PEth.
Direct and indirect biomarkers
Direct markers come from the way the body processes alcohol. Indirect markers show how alcohol may be affecting the body.
| Marker | Type | What to know |
|---|---|---|
| Urinary EtG (uEtG) | Direct | Detects alcohol use for up to 80 hours. Not influenced by cirrhosis. |
| Hair EtG (hEtG) | Direct | Tracks drinking for up to six months. Each 1 cm of scalp hair reflects about one month. |
| GGT (liver enzyme) | Indirect | Shows how alcohol may be affecting the body. Less specific to alcohol. |
| MCV (red blood cell size) | Indirect | Shows how alcohol may be affecting the body. Less specific to alcohol. |
Other direct markers, such as PEth, are covered on their own pages. Your care team chooses the test that fits your situation.
Reasons for alcohol testing
Sustained abstinence is the cornerstone of care for alcohol-associated liver disease. In the early stages, fatty liver and alcoholic hepatitis can often be reversed by stopping alcohol. An EtG result can show your team whether the plan is working.
Some indirect markers are harder to interpret in advanced liver disease. Urinary EtG is not influenced by cirrhosis, so it remains useful at this stage.
A hair EtG test covers up to six months. Your team may choose it when a single urine result would not give enough of the picture.
People with cirrhosis who keep drinking are not eligible for a liver transplant. Objective testing can be part of how a transplant team follows a person's progress. Learn more in [Alcohol-Related Liver Disease Treatment](/liver-therapies/alcohol-related-liver-disease-treatment).
Urine and hair collection
The test itself is simple. Your clinic will give you exact instructions for the type of sample it needs.
Timing and collection rules vary by clinic and lab. Ask your care team how to prepare.
EtG result meaning
A positive EtG result shows that alcohol was in the body during the test's detection window: up to 80 hours for urine, or up to six months for hair. It is a direct sign of alcohol, which makes it more specific than GGT or MCV.
A urine result reflects only the past few days. A hair result gives a longer view, but each 1 cm segment covers about one month, so it shows a pattern rather than single drinks. No single test replaces your drinking history, symptoms, and other liver tests.
This page does not list cutoff values or lab-specific rules. Labs set their own reporting ranges. Ask your care team what your number means and whether anything about your situation could affect it.
Alcohol-free support plan
Care for alcohol use disorder works best when it is integrated, including behavioral therapy, addiction counseling, and medicine when appropriate. Treating alcohol use disorder is essential to reaching abstinence and better liver outcomes.
Acamprosate and baclofen are useful in alcohol-related liver disease. Disulfiram should be avoided in severe disease, and naltrexone is not currently recommended there, because of possible liver toxicity. Your team decides what is safe for your liver.
Depending on how much you drink, quitting on your own may not be safe. Severe withdrawal can be life-threatening. Talk with your doctor before you stop, and call right away if you have severe symptoms.
Ask what your result means, how often you should be tested, which sample is best for you, and how the result fits with your other liver tests. Community and online support groups can also help.
A balanced, liver-friendly diet supports your liver, helps manage weight and blood sugar, and lowers the risk of other health problems during long-term follow-up.
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Common Questions
Urinary EtG can detect alcohol consumption for up to 80 hours. That is a little more than three days. After that window, a urine test may no longer show a recent drink. Labs may differ in how they report results, so ask your care team how your lab handles them and when a repeat test makes sense.
No. Urinary EtG is not influenced by the presence of cirrhosis. This matters because some indirect markers, such as GGT and MCV, can be harder to interpret in advanced liver disease. It is one reason urinary EtG is rated as superior to those markers. The result still needs to be read alongside your history and other liver tests.
A direct marker, such as EtG, comes from the way the body processes alcohol itself, so finding it shows that alcohol was in the body. An indirect marker, such as GGT or MCV, shows how alcohol may be affecting the body, for example through a liver enzyme or red blood cell size. Indirect markers are less specific to alcohol, so doctors often rely on direct markers to confirm recent or longer-term drinking.
No, EtG is not used to measure the amount you drank. The test shows that alcohol was present during its detection window: up to 80 hours for urine, or up to six months for hair. A hair result reflects a pattern, with each 1 cm segment covering about one month. Ask your care team how they use the result in your care.
Yes, often in the early stages. Fatty liver and alcoholic hepatitis can often be reversed by stopping alcohol. Scarring from cirrhosis is not reversible, but stopping alcohol can still slow or stop further damage and improve survival. Sustained abstinence is the cornerstone of treatment. If you drink heavily, talk with your doctor before you stop, because withdrawal can be dangerous.
Medical disclaimer: LiverDirectory provides educational information and a directory of providers. It does not provide medical advice, diagnosis, or treatment. Always consult a licensed physician regarding any medical condition.
