Can Drinking Alcohol the Night Before a Blood Test Affect Liver Enzymes? Here’s What You Should Know

If you have an upcoming blood test that includes a liver panel, you might be wondering whether that glass of wine—or more—will show up in your results.

The short answer: yes, drinking alcohol the night before your blood test can affect your liver enzyme levels. Even a single night of heavy drinking may cause a temporary rise in markers your doctor is monitoring.

This article explains:

• How alcohol affects liver function
  

• Which liver enzymes are typically tested
  

• Whether occasional drinking changes your results
  

• When to avoid alcohol before a test
  

• How to prepare for more accurate lab results
  

Let’s walk through what you need to know to feel prepared and informed.

What Do Liver Enzyme Tests Measure?

A liver panel (also known as a hepatic function panel or LFTs) is a common blood test that helps assess how well your liver is functioning. It typically includes:

• ALT (alanine aminotransferase)
  

• AST (aspartate aminotransferase)
  

• ALP (alkaline phosphatase)
  

• GGT (gamma-glutamyl transferase)
  

• Total bilirubin
  

• Albumin and total protein
  
  

Elevated levels of ALT and AST often suggest liver inflammation or damage, while GGT is particularly sensitive to alcohol intake. ALT is also referred to as SGPT in liver function tests, and it can be an early indicator of alcohol-related stress on the liver.

How Does Alcohol Affect Liver Enzymes?

When you consume alcohol, your liver works to break it down into non-toxic byproducts. In doing so, liver cells can become inflamed or stressed, especially if you drink heavily or regularly. This stress may temporarily raise levels of liver enzymes, even in people without underlying liver disease.

Alcohol can cause:

• Increased ALT and AST due to mild liver inflammation
  

• Elevated GGT, even with moderate alcohol use
  

• Changes in bilirubin levels, especially in chronic drinkers
  

• Fatty liver changes (steatosis), which may be seen in imaging or advanced blood testing

These effects are more pronounced in individuals with existing conditions such as fatty liver disease or early-stage alcoholic liver damage.

In some cases, persistent elevations can even signal serious underlying disease like liver cancer or hepatitis. If your enzymes remain high, your doctor might follow up with an acute hepatitis panel.

Can One Night of Drinking Affect Your Blood Test Results?

Yes—it can, especially depending on:

• How much you drank
  

• How close to the test you drank
  

• Your overall liver health
  

• Whether you were fasting or dehydrated
  

For example:

• A glass of wine with dinner is unlikely to make a major difference for most people.
  

• Three or more drinks in one evening, especially close to the time of testing, may lead to elevated AST, ALT, or GGT for up to 24–48 hours, and sometimes longer.
  

Even in healthy individuals, alcohol can cause a mild and temporary enzyme rise.

To better understand impact, it helps to know how much alcohol is in beer or wine and how your body metabolizes it.

When Should You Avoid Alcohol Before a Liver Blood Test?

If you're preparing for a test that includes liver enzymes, most healthcare providers recommend avoiding alcohol for at least 24 to 48 hours beforehand. This gives your body time to process and eliminate alcohol from your system.

Consider avoiding alcohol longer if:

• You’ve had elevated liver enzymes in the past
  

• You have fatty liver disease or other liver conditions
  

• You’ve been asked to fast before your test
  

• You drink alcohol frequently or heavily
  

Fasting typically means no food or drink except water for 8–12 hours before your blood draw. Alcohol not only affects the liver but may interfere with blood sugar, triglycerides, and hydration status—other markers that may also be checked during the same lab panel.

How Long Does Alcohol Stay in the Body?

The liver processes roughly one standard drink per hour. That means:

• A single beer or glass of wine may be cleared in about 2–3 hours
  

• Several drinks can linger in your system for 12–24 hours, depending on your body size, metabolism, and overall health
  

• Liver enzyme levels, however, may remain elevated for 1–2 days or more after drinking

This is especially true for GGT, which can take weeks to normalize after regular alcohol use.

Not sure what elevated results mean? Learn what high liver enzymes could be telling you.

What If You Accidentally Drank the Night Before Your Test?

If you had alcohol within 24 hours of your test, be honest with your healthcare provider. It doesn’t mean your results are invalid—but your doctor may interpret them differently knowing this context.

Let your provider know:

• How much you drank
  

• What time you stopped drinking
  

• Whether you had food or fasted
  

• Any symptoms you’re experiencing (like fatigue or abdominal pain)
  

You may be asked to repeat the test later for confirmation.

Signs That Alcohol May Be Affecting Your Liver

Even if you feel well, drinking—especially heavily or over time—can cause subtle liver changes that show up in blood work first.

Watch for:

• Mild right upper abdominal discomfort
  

• Fatigue or reduced energy
  

• Unexplained nausea or bloating
  

• Yellowing of the skin or eyes (jaundice)
  

• Dark urine or pale stool
  

• Frequent hangovers or poor tolerance to alcohol
  

If you notice these signs—or if your doctor flags abnormal liver tests—it may be time to take a closer look at your alcohol habits and overall liver health.

Experiencing unexplained symptoms? Understand what liver pain feels like and what can mimic it.

How to Prepare for Your Liver Enzyme Test

For the most accurate results:

• Avoid alcohol for 48 hours before your test
  

• Fast if your doctor recommends it (usually 8–12 hours)
  

• Drink plenty of water the day before
  

• Avoid strenuous exercise for 24 hours (which can also elevate AST)
  

• Let your provider know about any medications or supplements
  

Some over-the-counter drugs (like acetaminophen) and even herbal supplements can affect liver enzymes. Your doctor can advise whether to pause any before your test.

Key Takeaways

Protecting Your Liver Long-Term

While a single drink is unlikely to cause lasting harm, frequent or heavy alcohol use is one of the leading causes of preventable liver disease. Over time, it can lead to:

• Fatty liver disease
  

• Alcoholic hepatitis
  

• Fibrosis and cirrhosis
  

• Increased cancer risk
  

If you’re working on reducing alcohol or supporting liver recovery, your doctor may recommend regular monitoring with liver panels every 3–6 months.

Early action matters. A doctor-approved fatty liver diet plan, combined with reduced alcohol intake, can help your liver recover more effectively.

For those aiming to stay on track, at-home liver function tests can offer a convenient way to check enzyme levels between appointments—especially if you're making lifestyle changes.

Conclusion: Alcohol Can Impact Liver Test Results—Even After One Night

Drinking alcohol the night before a blood test can temporarily affect your liver enzyme levels, especially if you drink more than a small amount. For accurate results, it’s best to avoid alcohol for at least 1–2 days before your test and discuss your intake honestly with your provider.

Your liver is a resilient organ—but it depends on your choices. Small, consistent habits make a lasting difference.

Check In On Your Liver Health with Ribbon Checkup

Curious about your liver function? Ribbon Checkup offers at-home liver tests that let you track key health markers all from the comfort of your home. 

Related Resources

• Signs Your Liver Is Healing: What to Expect and How to Support Recovery

• How to Detox Your Liver: A Science-Backed Guide

• Fatty Liver Diet Plan PDF: A Doctor-Recommended 7-Day Meal Guide

References

References

Alatalo, P., Koivisto, H., K. Puukka, Hietala, J., Anttila, P., R. Bloigu, & Niemela, O. (2008). Biomarkers of Liver Status in Heavy Drinkers, Moderate Drinkers and Abstainers. Alcohol and Alcoholism, 44(2), 199–203. https://doi.org/10.1093/alcalc/agn099 

Barry, S. (2023, October 11). How to Prepare for a Blood Test. Retrieved May 26, 2025, from Healthline website: https://www.healthline.com/health/how-to-prepare-for-blood-test 

Clinic, C. (2021, December 3). How Long Does Alcohol Stay in Your System? Retrieved May 26, 2025, from Cleveland Clinic website: https://health.clevelandclinic.org/how-long-does-alcohol-stay-in-your-system 

Clinic, C. (2023a, August 29). A gamma-glutamyl transferase (GGT) test is a blood test used to diagnose liver or bile duct issues. Alcohol, medications and health issues can cause high GGT levels. Retrieved May 26, 2025, from Cleveland Clinic website: https://my.clevelandclinic.org/health/diagnostics/22055-gamma-glutamyl-transferase-ggt-test 

Clinic, C. (2023b, September 5). Elevated Liver Enzymes: What Is It, Causes, Prevention & Treatment. Retrieved May 26, 2025, from Cleveland Clinic website: https://my.clevelandclinic.org/health/symptoms/17679-elevated-liver-enzymes

Rani, D. R., & Singh, A. K. (2024). Effect of Alcohol Intake on Liver Function Tests. INTERNATIONAL JOURNAL of TOXICOLOGICAL and PHARMACOLOGICAL RESEARCH, 14(1). Retrieved from https://www.researchgate.net/publication/377382712_Effect_of_Alcohol_Intake_on_Liver_Function_Tests