If you perform a quick online search for the query ”how long does alcohol stay in your system,” you’ll receive thousands of results. It’s a common question many people ask, especially before getting behind the wheel.
While alcohol typically leaves the bloodstream within 12 to 24 hours, the time it takes to leave your system varies significantly depending on your age, weight, metabolism, how much you’ve had to drink, and the types of drinks you’ve consumed.
To help you practice safe alcohol consumption and avoid driving while impaired to protect yourself and others, read on to learn:
- How Long Does It Take Alcohol to Leave Your System?
- How Alcohol is Measured in the Body
- How Your Body Processes Alcohol
- Factors that Impact Alcohol Metabolism
- When You Start Feeling Alcohol’s Effects
- What It Actually Takes for Your Body to Become Sober
- When Is It Safe to Drive After Drinking Alcohol?
Want to join the fight against drunk driving? Discover how you can help solve the problem and make the roads safer for everyone.
How Long Does It Take Alcohol to Leave Your System?
So, when does alcohol leave your system? Well, it depends. The half-life of alcohol is typically four to five hours. This is the time it takes for the body to eliminate half of it. That said, alcohol normally leaves the bloodstream within 12 to 24 hours, but the time it takes to leave your system may vary depending on your age, gender, weight, metabolism, how much you’ve had to drink, and more.
The timeline may also vary significantly depending on the test type. For instance, a blood test might only detect alcohol for 12 hours after your last drink, while alcohol can show up on a hair follicle drug test months later.
Here’s an overview of typical detection timeframes, but keep in mind that results may vary significantly from one person to another:
| Test Type | Average Detection Window |
| Blood | Up to 12 hours |
| Saliva | 12 to 24 hours |
| Breath | 12 to 24 hours |
| Urine | 12 to 24 hours |
| Hair | Up to 90 days |
How Alcohol is Measured in the Body
Alcohol tests don’t measure the total amount of alcohol you’ve consumed. Instead, they measure your blood alcohol concentration (BAC). Your BAC or blood alcohol level indicates the percentage of alcohol in your system. For example, a BAC of 0.05% indicates there are 0.05 grams of alcohol per 100 milliliters of blood.
Here are the different tests medical and law enforcement professionals may conduct to measure alcohol in your system:
- Blood tests: These tests measure the amount of ethanol circulating in the bloodstream.
- Breath tests: Also known as a “breathalyzer test,” this test measures BAC by analyzing alcohol vapor in exhaled breath. Police officers often use it during roadside sobriety checks.
- Urine tests: These tests primarily look for alcohol metabolites, the substances produced when the body breaks down alcohol in the liver. Companies often use this test type to test employees for recent drug use.
- Saliva tests: Saliva tests can detect BAC shortly after drinking, but they aren’t as accurate as blood or breath tests.
- Hair tests: Like urine tests, hair tests look for alcohol metabolites such as ethyl glucuronide (EtG). These tests can detect alcohol use up to 90 days later by analyzing hair follicles.
How Your Body Processes Alcohol
When you consume alcohol, it enters your digestive system and is absorbed into the bloodstream through the stomach and the intestines. Once it’s in your bloodstream, your liver then breaks down the alcohol in your system using enzymes like alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH).
ADH first converts ethanol into a toxic compound called acetaldehyde. Then ALDH further processes it into acetate, which eventually converts to water and carbon dioxide that your body can eliminate safely.
Despite myths and marketing claims, no ”quick fixes” can accelerate how quickly the body processes alcohol. Your body metabolizes alcohol at a steady pace, with most people eliminating roughly 0.015 grams of alcohol per 100 milliliters of blood per hour.
This means that even if you try to sober up faster by drinking coffee, taking a cold shower, exercising, or consuming special supplements, it won’t speed up how fast your body eliminates alcohol.
Factors that Impact Alcohol Metabolism
While your liver breaks down alcohol at a relatively consistent rate, various factors may affect how quickly your body metabolizes and eliminates it. There’s no one-size-fits-all alcohol clearance timeline. Two people may drink the same amount yet experience different levels of impairment and elimination timelines. Factors that affect alcohol metabolism include:
Age
As you get older, your metabolism naturally slows down, and your liver becomes less efficient at eliminating alcohol. Older adults also tend to have less muscle mass and body water, leading to higher blood alcohol content from the same amount of alcohol compared to younger people.
Biological Sex
Women generally metabolize alcohol more slowly than men because they have lower levels of alcohol dehydrogenase, one of the enzymes that breaks down alcohol. Women also often have a higher body fat percentage and lower water content. This means that a woman will likely have a higher BAC than a man even after consuming the same amount of alcohol.
Body Composition
Your body size can significantly determine how alcohol distributes throughout your system because alcohol distributes primarily into body water. People with higher muscle mass and lower body fat typically process alcohol more efficiently because muscle tissue contains more water than fat tissue. This means a person with high body fat will likely have a higher BAC than a lean, muscular person after consuming the same amount of alcohol.
Food
Eating before, during, and after drinking can slow the absorption of alcohol into your bloodstream. Some foods that can reduce the time it takes your body to absorb alcohol include:
- Lean proteins like chicken breast, tuna, and eggs
- Whole carbs like brown rice, whole wheat pasta, and sweet potatoes
- Potassium-rich foods like avocados, bananas, and dried apricots
Medications
Some medications can significantly affect how your body breaks down alcohol. For instance, certain drugs can inhibit the enzymes that break down alcohol in the stomach and liver.
So, if you’re taking medications or have a health condition, consult your doctor to determine whether you can consume alcohol safely.
When You Start Feeling Alcohol’s Effects
You’ll typically start feeling alcohol’s effects within 5 to 10 minutes of your first drink, though this timing may vary depending on whether you’ve eaten, your age, body size, and how quickly you’re drinking. During this period, you may feel mild euphoria, relaxation, and a warming sensation throughout your body. These effects eventually build over time and tend to peak around 30 to 60 minutes after drinking.
How you feel doesn’t always match your BAC, though. While you might feel perfectly fine and capable of driving after drinking, your BAC may remain above legal limits. This disconnect between how you feel and your actual state can affect your coordination, judgment, and reaction time. That’s why you should never use how you ”feel” when deciding whether you’re sober enough to drive.
Wondering how to get home after a night out drinking? Check out our comprehensive guide on safe rides for impaired drivers.
What It Actually Takes for Your Body to Become Sober
Feeling sober and having a low BAC aren’t the same thing. While you might feel alert and sober after a few hours, your BAC could still be dangerously high. This false confidence is part of what contributes to drunk driving; people genuinely believe they’re sober when they aren’t.
This begs the question: How long does being drunk last? True sobriety requires time. Your liver takes about an hour to process each standard drink, and nothing can speed up the process. While cold showers, coffee, and exercise can make you feel more alert, none of these things can flush alcohol out of your system faster.
When Is It Safe to Drive After Drinking Alcohol?
The legal BAC limit in most U.S. states is 0.08%, but impairment may start before you reach this level. Even at 0.05%, your judgment and reaction time may decline, putting you and other road users at risk.
As a general guideline, alcohol typically takes at least one hour per standard drink to metabolize, but this can vary widely from person to person based on many factors. Because of that variability, timing alone should never be used to determine whether it’s safe to drive.
If you’ve consumed any alcohol, it’s safest not to drive at all. Instead, it’s always best to plan for an alternative ride, like a taxi, a rideshare service, or a designated driver.
Support Safe Alcohol Consumption with MADD
Thousands of deaths happen every year because someone made the fateful decision to get behind the wheel after drinking. In fact, in the U.S., alcohol is one of the leading causes of preventable deaths, with alcohol impaired accidents accounting for 32% of driving fatalities.
But you can be part of the solution and improve road safety. Practice safe, responsible consumption, and visit our Get Involved page to learn how you can make a difference and help save lives in your community.
