Your body clears alcohol at a fixed rate of about 0.015% blood alcohol concentration (BAC) per hour, which works out to roughly one standard drink every 60 to 90 minutes. But traces of alcohol and its byproducts can linger far longer depending on how they’re measured. A breath test can pick up alcohol for up to 24 hours, a urine test for up to 5 days, and a hair test for up to 90 days.
How Your Body Processes Alcohol
About 90 to 95% of the alcohol you drink is broken down in the liver through a two-step process. First, an enzyme converts alcohol into a toxic compound called acetaldehyde, a known carcinogen. Then a second enzyme quickly breaks acetaldehyde down into acetate, which the body converts into water and carbon dioxide for easy elimination. The small remainder leaves through your breath, sweat, and urine unchanged.
This process is essentially fixed. Your liver handles alcohol at 0.015% BAC per hour regardless of your gender, size, or body type. That rate is constant, meaning your body doesn’t speed up just because there’s more alcohol in your system. If your BAC is 0.08% (the legal driving limit in most U.S. states), it will take roughly five and a half hours to reach 0.00%.
Why the Timeline Varies Person to Person
While the liver’s processing rate is relatively consistent, how high your BAC climbs in the first place varies significantly. The higher it goes, the longer it takes to come back down. Several factors influence peak BAC:
- Body size and composition: People with more body water dilute alcohol more effectively, producing a lower BAC from the same number of drinks. People with higher body fat percentages tend to reach higher BAC levels because fat tissue doesn’t absorb alcohol the way water-rich muscle does.
- Biological sex: Women generally absorb more alcohol and take longer to process it than men, partly because of differences in body water content, muscle mass, and hormones. After the same number of drinks, women typically have higher blood alcohol levels.
- Food intake: Eating before or while drinking significantly changes the picture. Food slows alcohol absorption from the gut, resulting in a lower, later-occurring peak BAC. One study in the Annals of Emergency Medicine found that eating a meal temporarily increased the alcohol elimination rate by 86%, likely from enhanced enzyme activity and increased blood flow to the liver. That boost was temporary, fading within about four hours, but eating still helps by flattening the overall curve.
- Drinking history: Chronic heavy drinkers develop an additional metabolic pathway that can increase their elimination rate to roughly 0.025 to 0.035% per hour. This doesn’t mean heavy drinking is protective; it comes alongside liver damage and broader metabolic dysfunction.
Detection Windows by Test Type
How long alcohol is “detectable” depends entirely on what’s being tested and what the test is looking for. Some tests measure alcohol itself, while others detect metabolic byproducts that stick around much longer.
- Breath: A breathalyzer can detect alcohol for up to 24 hours, though 12 hours is more typical for moderate drinking.
- Blood: A blood test can detect alcohol for up to 12 hours after your last drink.
- Urine (standard): A basic urine test picks up alcohol for 12 to 24 hours.
- Urine (EtG): An EtG test looks for ethyl glucuronide, a byproduct your body produces when processing alcohol. These tests can detect drinking for up to 80 hours (roughly 3 days), and some sources cite up to 5 days depending on the amount consumed.
- Hair: A hair follicle test can detect alcohol use for up to 90 days.
EtG tests are commonly used in court-ordered monitoring, workplace programs, and treatment settings precisely because of their long detection window. They’re sensitive enough to flag even small amounts of alcohol, which is why incidental exposure (like hand sanitizer) can occasionally cause a positive result.
How Long Until You’re Actually Sober
Cleveland Clinic puts the half-life of alcohol at four to five hours, meaning your body eliminates half the alcohol in that time. Because you need about five half-lives to clear it completely, full elimination can take around 25 hours after heavy drinking. For more moderate consumption, the math is simpler: at 0.015% per hour, every standard drink adds roughly one hour to your clearance time.
Here’s a rough guide based on the 0.015% per hour rate. If you stop drinking at midnight with a BAC of 0.08%, you won’t hit 0.00% until about 5:30 a.m. If you had a heavier night and your BAC reached 0.15%, you’re looking at 10 hours, putting you at around 10:00 a.m. the next day. Many people are surprised to learn they can still be over the legal limit the morning after a night of heavy drinking.
Nothing Speeds It Up
Coffee, cold showers, exercise, and “sweating it out” do not increase the rate at which your liver processes alcohol. The enzymatic breakdown happens at a fixed pace, and no home remedy changes that. Coffee may make you feel more alert, but it doesn’t lower your BAC. You’re just a more awake version of drunk.
The only factor shown to temporarily speed up elimination is eating food, and even that effect is modest and short-lived. The practical takeaway: time is the only reliable way to sober up.
Alcohol and Breast Milk
Alcohol passes into breast milk at roughly the same concentration as your blood. The CDC recommends waiting at least 2 hours per drink before breastfeeding. One drink is detectable in breast milk for about 2 to 3 hours, two drinks for 4 to 5 hours, and three drinks for 6 to 8 hours. Pumping and dumping does not remove alcohol from breast milk any faster; the milk clears as your blood alcohol drops.