How Long Does Alcohol Stay in Your System?

Knowing how long alcohol (ethanol) remains in your system is important for avoiding dangerous interactions with medications as well as impairments in your physical and mental performance. While alcohol is not considered a controlled substance under the Controlled Substances Act (CSA), it is illegal to sell or serve to anyone under the age of 21 in the United States.

The metabolism of alcohol has been studied in detail, but many factors determine how long alcohol shows up on a drug test and how long it takes to be eliminated from your body. Depending on the type of test used as well as your age, body mass, genetics, sex, and overall health, alcohol is detectable from 10 hours to 90 days.

When misused, alcohol can do as much (or even more) overall harm as many illegal drugs. People who misuse alcohol also risk developing physical and psychological dependence and alcohol use disorder (AUD).

How Long Does It Take to Feel Effects?

You can start to feel the effects of alcohol in a matter of minutes. When ingested, alcohol is rapidly absorbed from the stomach and small intestine into your bloodstream before it travels to the central nervous system (brain and spinal cord). As a central nervous system depressant, alcohol impairs the communication of messages in your brain, altering your perceptions, emotions, movement, and senses.

In small amounts, you might feel more relaxed and open or less anxious, but the more you drink, the more intoxicated you’ll begin to feel. For some, this can mean being more talkative or very friendly, and others may begin to behave with anger or aggression.

Other signs of alcohol intoxication include:

• Euphoria
• Loss of coordination and balance
• Diminished inhibitions
• Poor judgment (such as driving under the influence or engaging in unprotected sex)
• Slowed reaction time
• Slurred speech

How Long Does Alcohol Last?

The half-life of ethanol is about 4 to 5 hours, which means it takes that long to eliminate half of the alcohol ingested from the bloodstream. For most people, alcohol is absorbed into the system more rapidly than it is metabolized.

For a person weighing 150 pounds, for example, one standard drink will increase their blood-alcohol concentration by about 0.02%, but the body can only remove about 0.016% per hour on average. Therefore, even if you consume only one drink per hour, your blood alcohol concentration (BAC) will continue to increase. If you drink more than one per hour, it rises much more rapidly.

The body metabolizes alcohol by oxidizing the ethanol to acetaldehyde. The acetaldehyde is broken down into acetic acid and then further broken down into carbon dioxide and water. Most of the alcohol you consume is metabolized in the liver, but about 5% of the alcohol you drink is excreted by the body through sweat, breath, urine, feces, and saliva.

Determining exactly how long alcohol is detectable in the body depends on many variables, including which kind of drug test is being used. Alcohol can be detected for a shorter time with some tests but can be visible for up to three months in others.

The following is an estimated range of times, or detection windows, during which alcohol can be detected by various testing methods.

Breath

Alcohol can be detected in your breath via a breathalyzer test for up to 24 hours.

Urine

Alcohol can be detected in urine for 10 to 12 hours via the traditional urine test.

Blood

Alcohol can show up in a blood test for up to 12 hours.

Saliva

A saliva test can be positive for alcohol from 24 to 48 hours.

Hair

Like many other drugs, alcohol can be detected with a hair follicle drug test for up to 90 days.

Test for Abstinence Versus Intoxication

A special test, known as the EtG test, is often given to confirm abstinence in a person who is required to maintain sobriety for legal or medical reasons. The EtG test measures a metabolite of alcohol known as ethyl glucuronide, which can be found in blood, hair, and nails, but it is typically done with a urine test. The EtG test can detect this alcohol metabolite for 3 to 5 days after consuming alcohol but does not accurately indicate if someone is currently intoxicated.

Factors That Affect Detection Time

The timetable for detecting alcohol in the body is also dependent upon variables such as metabolism, body mass, age, hydration level, physical activity, health conditions, and other factors, making it almost impossible to determine an exact time alcohol will show up on a drug test. Some of those factors include the following.

Genetics

Just as family history plays a role in the development of an alcohol use disorder, how quickly the body processes and excretes alcohol also has a genetic link.

Sex

Since women tend to have proportionally more body fat and less body water than men, alcohol tends to linger in their systems longer than men.

Body Fat

Again, the more fat you have, the longer the alcohol will stay in your body.

Ethnicity

Studies have found that people of East Asian descent are more likely to have trouble metabolizing alcohol since they don’t produce enough of a key enzyme that helps break down alcohol in the liver. Instead, a toxic byproduct of alcohol builds up in the blood and liver, dilates blood vessels, and causes flushing (redness and heat) in the face and neck, as well as headaches, dizziness, palpitations, and nausea. This reaction is known colloquially as “Asian flush” or “Asian glow.” 

Aging

As you get older, your liver works more slowly, so it takes longer to metabolize and excrete alcohol. Many aging adults also take medication that can affect liver function, slowing the process further.

Food Consumption

Roughly 20% of the ethanol in liquor is absorbed into the blood from the stomach and the rest from the small intestine. The longer alcohol stays in the stomach, the longer it takes to be absorbed and the slower the rate of intoxication. Eating before drinking and continuing to snack while you consume alcohol will slow the absorption and reduce its intoxicating impact, but it will prolong the detection period.

Medications

Certain medications can interfere with how alcohol is absorbed in the body and some may even enhance the effects and increase intoxication. Always be honest with your healthcare provider about how much alcohol you consume. Medications known to interact with alcohol include:

• Anti-anxiety medications
• Antidepressants
• Antibiotics
• Allergy medications
• Diabetes medications

Frequency and Speed of Use

How frequently and how fast you drink, as well as the alcohol content in your beverage, can all influence how long alcohol stays in your system. For example, if you engage in binge drinking—five or more drinks for men or four for women during a single drinking session—it can take many hours for the alcohol to completely clear from your system.

It is possible for your system to still have enough alcohol in it the following day that you could fail a urine or blood test for driving under the influence. You would have a problem trying to pass a test that is designed to detect the presence of any alcohol.

How to Get Alcohol Out of Your System

Regardless of how fast your body absorbs alcohol, it eliminates it at the average rate of 0.016 BAC per hour. Nothing you do will speed up the elimination process, including drinking coffee, drinking water, taking a shower, or even vomiting.

If you know that you are going to have to take a breath, blood, or urine test for the presence of alcohol in your system, the only way you can lower your blood alcohol content results is to delay taking the test as long as possible after your last drink, because only time will reduce your BAC.

The following table shows the length of time it takes for your body to eliminate alcohol at varying BAC levels.

The above times reflect the metabolism rate of a healthy, functioning liver. If you are a heavy or long-time drinker, your liver may require more time to eliminate alcohol from your body.

Symptoms of Overdose

Consuming large amounts of alcohol in a short period of time can result in alcohol poisoning, which is a medical emergency. According to the Centers for Disease Control and Prevention (CDC), an average of six people per day die of acute alcohol poisoning.

Drinking too much, too fast, or in combination with other drugs or medication can cause the areas of your brain that support your breathing, heart rate, and other essential life-supporting functions to begin to shut down.

• Breathing slowly or irregularly (less than eight times a minute or 10 seconds or more between any two breaths)
• Clammy, pale, or blue-tinged skin
• Confusion
• Decreased gag reflex (needed to prevent choking when vomiting)
• Extreme sleepiness or loss of consciousness
• Seizures
• Slow heart rate
• Low body temperature (hypothermia)
• Vomiting while unconscious (doesn't wake up during or after vomiting)

Getting Help

If you've been drinking heavily and/or regularly, suddenly stopping or cutting back on alcohol can cause physical and psychological symptoms of withdrawal. The severity will depend on how long you've been using alcohol and how much you usually drink. In severe cases, you can experience a possibly life-threatening type of alcohol withdrawal known as delirium tremens (or DTs), which can occur from two days to up to a week after your last drink.

When you're ready to quit or reduce the harm alcohol is causing to your health and life, there are many resources to help. Start by talking to your primary care physician. Many people also turn to support groups like Alcoholics Anonymous (AA). These in-person or online groups can help you feel supported and less alone as you navigate recovery.