Your body eliminates alcohol at a roughly fixed rate of one standard drink per hour. That means a single beer or glass of wine clears your bloodstream in about an hour, while a night of four or five drinks could take well into the next morning. But “staying in your system” depends on what’s being measured. Different tests can detect alcohol or its byproducts for anywhere from 12 hours to 6 months after your last drink.
How Your Body Processes Alcohol
Your liver does the heavy lifting. Two enzymes break alcohol down in stages: the first converts alcohol into a toxic intermediate compound called acetaldehyde (a known carcinogen), and the second converts that into acetate, which your body then breaks down into water and carbon dioxide. This process happens at a steady, predictable pace regardless of how much you drink. Your liver can only handle so much at once, so extra alcohol circulates in your blood until the liver catches up.
A secondary pathway kicks in after heavy drinking, but it handles a relatively small share of the workload. The bottom line is that there’s no shortcut. Coffee, cold showers, and food won’t speed up elimination once alcohol is already in your bloodstream. Time is the only thing that clears it.
One Drink Per Hour: What That Actually Means
A “standard drink” in the United States contains 0.6 ounces (14 grams) of pure alcohol. That equals roughly 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of distilled spirits. Your liver processes about one of these per hour.
The math is straightforward but easy to underestimate. A strong craft beer might count as 1.5 or 2 standard drinks. A generous pour of wine at a restaurant is often closer to 8 ounces than 5. If you have three large glasses of wine between 7 and 10 p.m., you may have consumed the equivalent of five or six standard drinks, meaning alcohol could still be in your blood at 3 or 4 a.m.
Detection Windows by Test Type
How long alcohol shows up depends entirely on which test is being used. Here’s what the different methods can detect:
- Blood test: Up to about 12 hours after your last drink. Blood tests measure the alcohol currently circulating in your system, so they reflect recent drinking only.
- Breathalyzer: Up to 24 hours, though 12 hours is more typical for moderate drinking. The range varies widely depending on how much you drank and individual body differences.
- Saliva test: Up to 24 hours. Oral fluid tests work on a similar timeline to breathalyzers.
- Urine test (EtG): Up to 48 hours after a few drinks, and sometimes 72 hours or longer after heavier drinking. EtG tests don’t detect alcohol itself but a byproduct your body creates while processing it, which lingers much longer.
- Hair test: 1 to 6 months, though it takes several weeks after drinking for markers to appear in a hair strand. Most results reflect the past 3 to 6 months because people trim their hair regularly.
The urine EtG test is the one that catches people off guard. Because it picks up a metabolic byproduct rather than alcohol itself, a night of heavy drinking on Friday could still produce a positive result on Sunday or even Monday morning.
Why Some People Process Alcohol Slower
The one-drink-per-hour rule is an average. Several factors push your actual rate higher or lower.
Biological Sex
Women generally absorb more alcohol and take longer to process it than men, even when drinking the same amount. The CDC attributes this to differences in body composition: women typically have less body water and more body fat relative to their size, which means the alcohol they drink is more concentrated in their bloodstream. Hormonal differences also play a role.
Body Size and Composition
A larger person with more muscle mass and body water will dilute the same amount of alcohol across a greater volume, resulting in a lower blood alcohol concentration. Someone smaller will reach a higher peak from the same number of drinks and take longer to clear it.
Age
As you get older, your body holds less water and your liver processes alcohol more slowly. Harvard Health notes that after drinking the same amount, older adults end up with higher blood alcohol levels than younger people. This is one reason alcohol hits harder with age, even if your drinking habits haven’t changed.
Food in Your Stomach
Eating before or while drinking slows the rate at which alcohol enters your bloodstream. Solid meals are more effective than liquid ones because they delay the movement of stomach contents into the small intestine, where most absorption happens. This won’t change how long it takes your liver to process the alcohol, but it lowers your peak blood alcohol level and spreads the absorption over a longer window.
Liver Health
Any condition that compromises liver function, from fatty liver disease to hepatitis, can reduce your body’s ability to break down alcohol efficiently. People with liver damage may metabolize alcohol significantly slower than the typical rate.
Blood Alcohol Concentration and Timing
Your blood alcohol concentration (BAC) rises quickly after drinking, usually peaking 30 to 60 minutes after your last drink on an empty stomach, or somewhat later if you’ve eaten. From that peak, it drops at the steady rate your liver can manage.
For context, the legal driving limit in most U.S. states is 0.08%. A 160-pound man might reach that level after about four standard drinks in an hour. From a BAC of 0.08%, it would take roughly five hours of zero additional drinking to return to 0.00%. At higher BAC levels, the timeline extends proportionally. Someone who stops drinking at midnight with a BAC of 0.15% may not reach zero until 9 or 10 a.m.
This is worth keeping in mind the morning after heavy drinking. Feeling sober and being at a BAC of 0.00% are not the same thing. Many people unknowingly drive with alcohol still in their system the morning after a big night out, even though they feel fine.
What You Can and Can’t Control
You can’t speed up alcohol elimination once it’s in your blood. Your liver works at its own pace. What you can influence is how quickly alcohol enters your system in the first place. Eating a solid meal before drinking, pacing yourself to roughly one drink per hour, and choosing lower-alcohol beverages all help keep your BAC from spiking. Drinking water between alcoholic drinks helps with hydration but doesn’t accelerate metabolism.
If you’re concerned about a specific test, the detection windows above give you a realistic framework. For blood and breath tests, you’re generally looking at 12 to 24 hours. For urine EtG tests, plan on at least 48 hours and potentially longer after heavy drinking. For hair tests, months of abstinence are needed to produce a clean result.