When you take a sip of alcohol, your body begins metabolizing it almost immediately. The rate at which your body metabolizes and eliminates alcohol from your system can vary based on genetics, the scope of alcohol use, and factors like diet and hydration.

In this article, you will learn:

  • How the body metabolizes alcohol
  • Factors that affect how long alcohol stays in your body
  • How long alcohol stays in the system
  • How to flush alcohol from your body safely

How is Alcohol Metabolized?

Metabolism refers to the body’s process of breaking down a substance to be absorbed, used as energy, or eliminated from the body. All food, drinks, and drugs go through the process of metabolism, including alcohol. Half-life describes how quickly it takes the body to metabolize and eliminate half of a dose of a substance from the body. It takes 4-5 half lives to eliminate a substance from the body.

When it comes to alcohol, it is absorbed by the gastrointestinal tract, with 20% being absorbed through the stomach and 80% absorbed by the upper small intestine tissue lining.[1] It is absorbed into the bloodstream where it circulates throughout the body until it reaches the liver where it is metabolized.

Alcohol is broken down by the liver by enzymes called alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). ADH metabolizes alcohol into acetaldehyde, a carcinogen and toxic substance. Acetaldehyde is further broken down into acetate which is broken down into water and carbon dioxide before being eliminated from the body.[2]

When the body is done processing alcohol, it is eliminated through urine, sweat, and breath.

The body processes alcohol quickly and the effects can be felt just 10-15 minutes after drinking alcohol. The half-life of alcohol is 4-5 hours, so it can take 20-25 hours for alcohol to leave the system completely and for blood alcohol content to go back to zero.[3]

Measuring Levels of Alcohol in the Body

There is a unique and accurate way to measure the amount of alcohol that is circulating in your bloodstream. It involves breathing into a breathalyzer device which calculates blood alcohol concentration or BAC.

BAC measures alcohol as a percentage that describes the weight of alcohol in milligrams found per unit of volume in the blood or breath in milliliters. One’s BAC depends not only on the amount of alcohol consumed, but also on individual factors such as genetics, age, weight, and the presence or absence of food in the stomach.

A standard drink can increase BAC levels by approximately 0.02 in 45 to 60 minutes.[4] A standard drink is the equivalent of:

  • 12 ounces of beer (with about 5% alcohol content)
  • 5 ounces of wine (with about 12% alcohol content)
  • 1.5 ounces of distilled spirits or liquor (with about 40% alcohol content)

A healthy person can absorb one standard drink every 60 minutes. However, when drinking cocktails, taking shots, or binge drinking, it is easy to drink several standard drinks in under an hour, increasing BAC levels and leading to intoxication.

At 0.02-0.04% BAC, some effects may be noticeable, such as mild relaxation and a slight feeling of euphoria. There might also be a slight impairment of judgment and coordination. At 0.05-0.07% BAC, the effects of alcohol become more pronounced, including decreased inhibition, impaired judgment, reduced coordination, and decreased ability to track moving objects. Driving abilities may start becoming impaired.[5]

In most jurisdictions, a BAC of 0.08% is considered legally intoxicated for driving purposes. At this level, there’s a significant impairment of motor skills, reaction time, and judgment. This greatly increases the risk of accidents while driving.

Factors that Affect How Long Alcohol Stays in Your System

For the average healthy individual, the body can process 15-25 mg of alcohol per hour, or about one standard drink an hour.[6] The type and strength of the alcohol can affect this, as well as several additional factors that can affect the amount of time it takes the body to process the alcohol consumed.

These factors include:

  • Amount of alcohol consumed – The body will eliminate one drink faster than it will several drinks. Heavier drinkers will eliminate alcohol more slowly.
  • Gender – Women have a higher percentage of body fat and lower percentage of water in their bodies. This causes women to metabolize alcohol more slowly than men.
  • Age – Younger people generally have faster metabolisms and can process alcohol more quickly.
  • Food – Since alcohol is absorbed in the digestive tract, the presence of food in the stomach can affect the absorption and elimination rates.
  • Medication – Certain medications, including some antibiotics and antidepressants, can affect how quickly your body processes alcohol.[7]
  • Body composition – People who weigh less are smaller, so they reach higher levels of BAC from drinking the same amount of alcohol as larger people.

How Long Does Alcohol Stay in the Body?

How long alcohol stays in your system can vary greatly by the factors listed above as well as the type of test used. The following are estimated detection times for alcohol testing.


Depending on the amount of alcohol consumed, it can be detected by a breathalyzer device for 12-24 hours after the last drink. Breathalyzers are often the first line for detecting drunk drivers, so you may be asked to blow into one if you get pulled over and are suspected of driving under the influence.

Urine Test

The most popular type of drug test is a urine test. They are often used by employers for pre-employment screening. Alcohol can be detected by a urine test for 12-24 hours after the last drink. In heavy drinkers, it may be present for 72 hours or more.

Blood Test

Blood tests are used to confirm intoxication because they have a short detection window. Alcohol can stay in your blood for up to 12 hours.

Saliva Test

Saliva tests can detect alcohol for up to 12 hours after the last drink.

Hair Test

A hair test can detect alcohol or recent drug use for up to 90 days.

How to Flush Alcohol Out of Your System

Despite popular belief, drinking more water, sleeping, having a coffee, and taking a hot shower are not effective ways to flush alcohol out of your body. These methods may help you be more alert or feel better, but they will not sober you up faster or make alcohol leave your system more quickly. Instead, it’s best to have something to eat, avoid driving or operating machinery, and wait until the effects of alcohol wear off.

When it comes to metabolizing alcohol, time is the only factor that truly works. Your liver processes alcohol at a constant rate, typically eliminating about one standard drink per hour. No amount of water, sleep, coffee, or showers can change this natural process. In fact, attempting to speed up the process through excessive water consumption or other methods could be dangerous, potentially leading to vomiting and dehydration or other health issues.

The Risks of Drinking too Much Alcohol

Drinking too much alcohol too quickly can be harmful for your health. In excess, alcohol abuse can result in an overdose.

Symptoms of alcohol poisoning or overdose include:[8]

  • Confusion
  • Vomiting
  • Seizures
  • Slow or irregular breathing
  • Hypothermia (low body temperature)
  • Pale or bluish skin
  • Unconsciousness
  • Inability to wake up
  • Severe dehydration
  • Slurred speech
  • Loss of coordination
  • Stupor
  • Passing out

The risk for overdose increases when people binge drink, which is defined as having more than four drinks in two hours for women or more than five drinks in two hours for men.[9] Mixing alcohol with opioids, benzodiazepines, or other drugs can also increase the overdose risk.

People who abuse alcohol regularly are likely to experience poor decision making and social issues. They may develop increased anxiety, depression, and other mental health problems.

Not only that, but alcohol-related deaths are the fourth-leading cause of preventable death in the United States. Each year, approximately 178,000 people in the U.S. die as a result of excessive alcohol use–a 29% increase from 2016-2017.[10]

Long-term alcohol abuse can increase the risk of several serious health conditions, including:

  • Liver disease
  • Kidney disease
  • Cardiovascular disease
  • Neurological disorders
  • Pancreatitis
  • Gastritis
  • Cancer (especially of the liver, mouth, throat, esophagus, and colon)
  • Weakened immune system
  • Malnutrition
  • Mental health disorders (such as depression and anxiety)
  • Social and interpersonal problems
  • Alcohol dependence or addiction
  • Cognitive impairment

Quitting drinking and seeking help from a substance abuse treatment facility can help restore physical and mental health and prevent the progression of alcohol-related diseases.

Get Help for Alcohol Addiction Now

If you or a loved one are struggling with alcohol use disorder, the time to get help is now. Reach out to First Step Behavioral Health today to learn about our compassionate alcohol detox and treatment programs. We’re available 24 hours a day to help you take the first step toward recovery.


  1. Delgado Community College: Information on Alcohol Hazards
  2. National Institute on Alcohol Abuse and Alcoholism (NIAAA): Alcohol Metabolism
  3. National Library of Medicine: Alcohol in the body
  4. Centers for Disease Control and Prevention: Alcohol and Public Health
  5. University of Notre Dame: Blood Alcohol Concentration
  6. National Institute on Alcohol Abuse and Alcoholism (NIAAA): The Basics: Defining How Much Alcohol is Too Much
  7. National Institute on Alcohol Abuse and Alcoholism (NIAAA): Alcohol-Medication Interactions: Potentially Dangerous Mixes
  8. National Institute on Alcohol Abuse and Alcoholism (NIAAA): Understanding the Dangers of Alcohol Overdose
  9. Centers for Disease Control and Prevention (CDC): Binge Drinking
  10. Centers for Disease Control and Prevention (CDC): Deaths from Excessive Alcohol Use in the United States

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