Alcohol is mostly cleared from your bloodstream within 12 to 24 hours after your last drink, but it can show up on certain tests for days or even months depending on what’s being measured. Your liver processes roughly 95% of the alcohol you consume, breaking it down at a relatively fixed rate. The remaining 5% leaves through your breath, urine, and sweat.
How Fast Your Body Processes Alcohol
Your liver eliminates alcohol from the blood at a rate between 10 and 30 mg/dL per hour. For most people, this works out to roughly one standard drink per hour, though the actual speed depends heavily on your liver size, body composition, and genetics. A standard drink in the U.S. contains about 14 grams of pure alcohol, which is the amount in a 12-ounce beer, a 5-ounce glass of wine, or a 1.5-ounce shot of liquor.
This rate is essentially fixed. Unlike many other substances, your body can’t speed up alcohol metabolism just because there’s more of it in your system. So if you’ve had five drinks, your liver still processes them one at a time, and it could take five or more hours just to clear your blood. Nothing you do (coffee, cold showers, “sweating it out”) changes this timeline.
Detection Windows by Test Type
How long alcohol is “in your body” depends entirely on which test is used. Here’s how the windows break down:
- Blood and breath: Alcohol is typically detectable for 12 to 24 hours after your last drink, depending on how much you consumed. These tests measure active alcohol in your system.
- Saliva: Up to 24 hours, according to Cleveland Clinic. Oral fluid tests are becoming more common in workplace screening.
- Standard urine test: Roughly 12 to 24 hours for a conventional ethanol urine test, similar to blood.
- EtG urine test: This is the one that catches people off guard. EtG (ethyl glucuronide) is a byproduct your body creates when processing alcohol, and it lingers much longer than alcohol itself. After a few drinks, EtG can show up in urine for up to 48 hours. After heavier drinking, it can be detected 72 hours or longer.
- Hair test: Hair follicle testing can detect alcohol use for 1 to 6 months, making it the longest detection window available.
If you’re facing a specific type of test, the distinction between measuring alcohol itself and measuring its byproducts is critical. A breath test the morning after a moderate night out will likely come back clean. An EtG urine test two days later might not.
Why It Takes Longer for Some People
Several factors determine where you fall on the 10 to 30 mg/dL per hour elimination spectrum. The biggest ones are body size, biological sex, age, and genetics.
Women generally reach higher blood alcohol levels than men after drinking the same amount, even at the same body weight. The reason is body composition: women typically carry a lower proportion of body water, so alcohol is distributed in a smaller volume of fluid and becomes more concentrated. Women also tend to have smaller liver volumes and lower lean body mass, which translates to slower elimination rates measured in grams per hour.
Genetics play a significant role too. Variations in the enzymes that break down alcohol can make a real difference. One genetic variant of a key liver enzyme has 2.5 times the alcohol-processing capacity of another variant. On the flip side, some people carry gene variants that slow the breakdown of acetaldehyde, a toxic intermediate compound your liver produces while processing alcohol. This is the same mechanism behind the “Asian flush” reaction, and it means acetaldehyde builds up faster than it can be cleared.
Age matters as well. Older adults tend to have less body water relative to their weight, which means alcohol concentrations run higher from the same amount of drinking. Liver function also declines with age, further slowing the process.
How Food Changes the Timeline
Eating before or while drinking is one of the few things that genuinely affects how alcohol moves through your body. Food slows the rate at which alcohol is absorbed from your stomach into your bloodstream, which lowers your peak blood alcohol concentration. You still absorb the same total amount of alcohol, but the peak is blunted and spread out over a longer period.
Research shows that eating shortly after drinking reduces the peak concentration of alcohol in the body, though the overall elimination rate stays about the same. In practical terms, this means food won’t help you sober up faster once alcohol is already in your blood, but eating beforehand can keep your blood alcohol level from spiking as high in the first place. A lower peak means less impairment and a shorter window before you’re back to zero.
What “One Drink Per Hour” Actually Means
The common advice that your body processes “about one drink per hour” is a reasonable rough estimate, but it hides a lot of variability. A small woman with certain genetic profiles might process alcohol at half the rate of a large man. If you had four drinks between 8 and 10 p.m., a rough estimate puts you at zero blood alcohol sometime between midnight and 2 a.m., but for some people it could take until 4 a.m. or later.
It’s also easy to undercount drinks. A generous pour of wine at home is often 7 or 8 ounces rather than the 5-ounce standard, and craft beers frequently run 7 to 9% alcohol instead of the 5% assumed in a “standard drink.” Two of those craft beers could count as three or four standard drinks, pushing your clearance time well past what you’d expect.
Chronic Drinking Changes the Equation
Regular heavy drinking alters how your liver handles alcohol at a cellular level. With repeated exposure, the liver ramps up activity of a secondary processing pathway that generates more harmful byproducts, including reactive oxygen species that damage liver cells over time. This can initially make a heavy drinker appear to “tolerate” alcohol better, since the liver is working harder to break it down. But it comes at a cost to liver health, and as liver damage accumulates, processing slows down again.
People with alcohol-related liver damage can take significantly longer to clear alcohol from their systems. The same is true for anyone with liver disease from other causes. If your liver is compromised, all the estimates above shift longer.