What Is Ethyl Glucuronide on a Drug Test?

What Is Ethyl Glucuronide on a Drug Test?

Ethyl glucuronide, also called EtG, is a biomarker that shows if someone has been using alcohol. It is not the alcohol itself, but a metabolite—something your body makes when it breaks down alcohol. This special compound can be found in your urine, blood, hair, and even saliva. When a drug test checks for alcohol, EtG is often what it looks for.

Doctors, probation officers, and health care providers use EtG tests to learn more about substance abuse, sobriety, or if a patient is following a plan to avoid alcohol. EtG testing is used in many places like primary care, pathology, mental health centers, or during pregnancy care.

How EtG Is Made in the Body

When you drink alcohol, your body works hard to get rid of it. The liver breaks it down using an enzyme called alcohol dehydrogenase. After this process, the alcohol turns into something called acetaldehyde, then into acid forms like fatty acid or other chemicals.

Some of that alcohol goes through a process with another enzyme called glucuronosyltransferase. This turns alcohol into ethyl glucuronide (EtG). Another compound, ethyl sulfate, is also made. These metabolites stay in your system longer than alcohol itself.

Why Ethyl Glucuronide Is Important

EtG is a key biomarker because it sticks around longer than alcohol. While a breathalyzer or blood alcohol content (BAC) test only shows recent drinking, EtG testing can show alcohol use from up to 80 hours after drinking. That’s more than 3 days!

This helps in many ways:

• Checking if a patient is staying sober.

• Helping probation or court programs.

• Tracking binge drinking or dangerous behavior.

• Helping in substance abuse treatment.

Where EtG Is Found in the Body

EtG can be found in many body fluids and parts:

Urine

A urine test is the most common way to check for EtG. The person provides a sample, and it is tested in a lab. This urinalysis is simple and cost-effective.

Blood

EtG can also be found in whole blood, but it stays for a shorter time than in urine.

Hair

EtG builds up in hair over time. This type of test can show drinking patterns from weeks or months ago.

Saliva

Some new tests can check EtG in saliva, though this method is still in research stages.

How EtG Testing Works

EtG is detected using toxicology tools in a lab. The two most common methods are:

Immunoassay

This method is fast and checks for EtG by using antibodies. It’s useful but may sometimes pick up things that aren’t alcohol, like hand sanitizer or mouthwash. That’s why sensitivity and specificity are important.

Chromatography and Mass Spectrometry

This method is more accurate. It uses machines to separate chemicals and measure EtG levels. It’s used when results need to be exact, like in pathology labs or probation testing. These methods are often combined and known as ELISA, LC-MS/MS, or GC-MS.

What Is a Normal EtG Level?

There is no universal reference range, but many labs use the following:

• Below 100 ng/mL: May mean no alcohol or very low levels.

• 100–500 ng/mL: Could be from incidental exposure (like mouthwash).

• Over 500 ng/mL: Likely alcohol use.

Doctors and counselors must also look at behavior, medicine use, and other factors like gender, fluid intake, or even disease (like diabetes or type 2 diabetes) that could affect results.

Can EtG Be Affected by Other Things?

Yes, EtG tests can sometimes pick up alcohol from non-drinking sources. This includes:

• Hand sanitizer

• Wine vinegar

• Fermentation from bacteria like escherichia coli in the body

• Some medications or foods

This is why doctors look at the whole picture and may confirm results using mass spectrometry.

How Long Does EtG Stay in the Body?

EtG stays longer than alcohol. Here’s a rough guide:

• Urine: Up to 80 hours

• Blood: Up to 24 hours

• Hair: Up to 90 days

• Saliva: About 12 to 24 hours

The time can change based on your metabolism, how much you drank, your organ function, and how much fluid you drank after.

EtG and Alcohol Abstinence

People in recovery programs may need to show abstinence from alcohol. EtG helps track that. Some rehab centers also test phosphatidylethanol (PEth), another biomarker for alcohol, and carbohydrate deficient transferrin (CDT) in blood tests to see long-term alcohol use.

EtG helps keep people honest and also helps build trust between patient and provider. It also helps in psychiatry when alcohol use could affect mental health treatment or medication plans.

Is EtG Testing Used in Addiction Treatment?

Yes. Many substance abuse treatment programs use EtG tests. It helps in:

• Watching for relapse

• Creating better treatment plans

• Helping patients stay accountable

• Keeping track of medication and sobriety

EtG Testing in Research and Health Care

Doctors and scientists use EtG in research to learn more about how alcohol affects the body. They study in vitro (in the lab) and with real people to see how alcohol changes the brain, liver, and behavior.

EtG testing also helps with health care planning. Insurance like Medicare may use it to check on treatment progress.

EtG and Other Drug Testing

EtG tests only check for alcohol, not other drugs like opioid, methamphetamine, or tetrahydrocannabinol (THC). But labs can test for those too using other assays.

Many programs use full panels to check for multiple drugs, including alcohol, opiate, stimulants, and more.

What If the EtG Test Is Positive?

If your test is positive, your doctor or counselor will talk with you. They may:

• Ask about any recent alcohol use

• Check if you used hand sanitizer or alcohol-based products

• Look at medications you take

• Repeat the test using chromatography or mass spectrometry for accuracy

It’s important to be honest. A positive EtG doesn’t always mean someone drank alcohol on purpose, but it must be reviewed carefully.

Tips to Avoid False Positives

To stay safe and avoid false test results:

• Don’t use alcohol-based hand sanitizer or mouthwash

• Be careful with wine in food or fermented products

• Tell your doctor about all medicine or vitamins you take

• Drink lots of water to stay healthy, but it won’t “wash out” EtG