How Long Does It Take to Get Alcohol Out of Your Body?

Your liver clears alcohol from your bloodstream at a roughly fixed rate, averaging about 15 milligrams per deciliter per hour for a moderate drinker. That translates, very loosely, to about one standard drink every 60 to 90 minutes. But the full answer depends on how much you drank, your body composition, your genetics, and even whether you’ve had surgery on your stomach. It also depends on what you mean by “out of your body,” because some metabolic byproducts linger in urine for days and in hair for months after the alcohol itself is long gone.

The Rate Your Liver Actually Works

Alcohol is processed almost entirely by the liver. Somewhere between 92 and 98 percent of the ethanol you drink is broken down there by enzymes, with only a small fraction leaving through your breath, urine, and sweat.¹ The main enzyme involved gets overwhelmed at fairly low concentrations, so once your blood alcohol is above roughly 15 to 20 mg/dL, your liver is working at full capacity. From that point forward, it burns through alcohol at a steady pace rather than speeding up as levels climb. That steady pace varies from person to person, anywhere from about 10 to 35 mg/dL per hour, with 15 mg/dL per hour being a commonly cited average.¹

To put that in everyday terms: if you have a blood alcohol concentration (BAC) of 0.08 percent, which is the legal driving limit in most of the United States, it would take roughly five to six hours for your body to bring that back to zero at the average rate. If you spent a night drinking heavily and reached a BAC of 0.15 or 0.20 percent, you could be looking at ten hours or more. Morning-after impairment is real and surprisingly common, because people underestimate how long it takes for a high BAC to fully clear.

How Drink Type and Food Change the Equation

The elimination rate is fairly stable, but absorption, the front end of the process, is where a lot of variability happens. A study that gave participants the same total dose of alcohol as beer, wine, or vodka-and-tonic found meaningful differences. Spirits produced a peak BAC of about 77 mg/dL, wine about 62 mg/dL, and beer about 50 mg/dL, even though the actual ethanol dose was identical. Spirits also peaked fastest, at around 36 minutes, compared with about 54 minutes for wine and 62 minutes for beer.² The overall bioavailability of alcohol from beer was lower, meaning your body absorbed less of the total ethanol from beer than from vodka.

A higher peak means more time until you’re back at zero, even though the liver’s clearance rate doesn’t change. So two people who drink “the same amount of alcohol” in different forms can end up on noticeably different timelines.

Food also matters, though perhaps not in the way you’d expect. Eating a meal before drinking slows absorption and reduces the peak BAC, which sounds like it would help you clear alcohol faster. But research on this found that while the elimination rate was slightly lower after a meal (0.017 percent per hour versus 0.020 on an empty stomach), the total time to reach zero BAC was essentially the same: about five hours in both conditions.³ Food smooths the curve but doesn’t dramatically shorten the tail. The practical benefit is that eating keeps you from hitting a dangerously high peak, not that it gets alcohol out of your system faster.

Why Women Generally Clear Alcohol More Slowly

Women tend to reach higher blood alcohol concentrations than men after drinking the same amount, even when the dose is adjusted for body weight. The primary reason is body composition: women on average have less total body water than men, so the same dose of alcohol is diluted into a smaller volume.⁴ A higher peak BAC means a longer wait until it clears. There’s also evidence that gastric metabolism of alcohol, the small amount of breakdown that happens in the stomach lining before ethanol even reaches the bloodstream, is lower in women, compounding the difference.

This is one of the reasons standard drink-counting advice can be misleading. A 130-pound woman and a 200-pound man drinking “two drinks” are not having the same biochemical experience. The woman will likely peak higher and take longer to return to zero.

Genetic Differences That Change How Fast You Metabolize Alcohol

Beyond sex and body size, inherited enzyme variants create real differences in alcohol processing speed. The two key enzymes are alcohol dehydrogenase (ADH), which converts ethanol into acetaldehyde, and aldehyde dehydrogenase (ALDH), which converts that toxic intermediate into harmless acetate. Variants in the genes for both enzymes are common in certain populations, especially among people of East Asian descent.

The most well-known variant involves the ALDH2 gene. People who carry two copies of the ALDH2*2 variant produce a nonfunctional version of the enzyme, meaning acetaldehyde builds up rapidly in their blood. This causes intense facial flushing, nausea, and a rapid heartbeat after even small amounts of alcohol.⁵ The ALDH2*2 variant is present in East Asian populations but essentially absent in people of European and African descent.⁵ Interestingly, the presence of ALDH2*2 is associated with slower overall alcohol metabolism, not faster, despite the intense reaction it triggers.⁶

On the ADH side, variants like ADH2*2 and ADH3*1 encode high-activity forms of the enzyme that convert ethanol to acetaldehyde faster. People carrying these alleles metabolize alcohol slightly more quickly, but also experience more flushing because the acetaldehyde is produced faster than it can be cleared.⁶ The net effect on how long it takes to be “alcohol-free” depends on which combination of variants a person carries, and there is enormous individual variability even among people with the same genotype.

These genetic differences are part of why the 10-to-35 mg/dL-per-hour range for elimination is so wide. Two healthy people of similar weight can metabolize the same number of drinks on meaningfully different timelines.

Blood and Breath vs. Urine vs. Hair

When people ask how long alcohol stays “in the body,” they often really want to know how long a test can detect it. The answer depends entirely on what’s being tested and which substance the test looks for.

Ethanol itself disappears from blood and breath relatively quickly, following the elimination curve described above. Standard breathalyzers work on the principle that a known volume of exhaled air contains a predictable fraction of the alcohol in your blood, typically assuming a blood-to-breath ratio of 2300 to 1.⁷ Once your BAC is at zero, a breath test won’t find anything.

Urine testing for ethanol itself has a similarly short window. But many workplace and forensic tests don’t look for ethanol directly. Instead, they look for ethyl glucuronide (EtG), a metabolic byproduct that the body produces in small amounts during alcohol breakdown. EtG hangs around much longer. In moderate drinkers after a single episode, it can be detected for roughly 24 to 48 hours. In heavy drinkers during detoxification, the picture is dramatically different: one study found individual detection windows of about 40 to 130 hours, with a median of 78 hours, before EtG fell below standard cutoff levels.⁸ That means a heavy drinker could test positive for EtG more than five days after their last drink. Another related marker, ethyl sulfate (EtS), tracks on a comparable timeline and is often tested alongside EtG.⁹

It’s worth noting that EtG can show up at detectable levels from sources other than drinking. Hand sanitizer exposure, certain mouthwashes, and even fermented foods have been reported to produce low-level positive EtG results. This is why cutoff thresholds and confirmatory testing exist, but it does occasionally create headaches for people in court-ordered monitoring programs.

Hair testing extends the window even further. Both EtG and fatty acid ethyl esters (FAEEs) are deposited into hair during growth, creating a record of alcohol exposure that can stretch back months. These markers are used primarily in forensic and child-protection settings rather than for acute detection.¹⁰ The concentrations in hair reflect total alcohol exposure over time rather than any single drinking event.¹¹ Hair grows roughly one centimeter per month, so a three-centimeter sample represents approximately three months of drinking history.

Wearable Alcohol Monitors and the Lag Problem

Transdermal alcohol sensors, the kind worn on the ankle or wrist, measure ethanol that diffuses through the skin. Court-ordered SCRAM ankle monitors are the best-known example, but wrist-worn consumer devices are becoming more common. These devices have a built-in limitation: they’re measuring alcohol that has already passed through several tissue layers, which introduces a significant time delay.

A systematic review of wearable transdermal sensors found that SCRAM readings peak about 120 minutes after peak breath alcohol. Looking across the full breath-alcohol curve, SCRAM lagged by an average of 69 minutes. Some studies found even longer delays, with mean transdermal peak delays of four and a half hours relative to blood alcohol peaks. Wrist-worn devices performed somewhat differently; one device lagged breath alcohol peaks by about 24 minutes.¹²

What this means practically is that a transdermal monitor will still be registering alcohol well after your blood has cleared. If you’re wearing one for legal compliance, the device can detect a drinking episode that ended hours earlier. It’s also why these devices aren’t ideal for real-time decisions about whether it’s safe to drive, since they’re showing you where your blood alcohol was, not where it is now.

How Gastric Bypass Surgery Changes Everything

People who have undergone Roux-en-Y gastric bypass (RYGB) process alcohol in a fundamentally different way. The surgery reroutes the digestive tract so that food and drink bypass most of the stomach and the upper portion of the small intestine. This removes much of the stomach’s limited ability to break down alcohol before it hits the bloodstream, and the shortened transit means ethanol gets absorbed much faster.

The results are striking. In one study, post-bypass patients reached a mean peak BAC of about 138 mg/dL (well above the legal limit) after drinking a controlled dose of alcohol, and they hit that peak in an average of just five minutes.¹³ For context, a typical person without bypass surgery peaks in 30 to 60 minutes. Another study tracked patients before surgery and at three and six months after and found that peak BAC roughly tripled by six months (from 0.024 to 0.088 percent), and the time to return to zero lengthened from 49 minutes pre-surgery to 88 minutes at six months.¹⁴ An earlier study similarly found that bypass patients had both a higher peak and a longer time to clear alcohol completely compared to controls.¹⁵

This effect seems to persist long after the initial recovery from surgery and catches many patients off guard. A single glass of wine after bypass can produce impairment that previously would have required two or three glasses. Surgeons and bariatric programs increasingly counsel patients about this, but the message doesn’t always land. If you’ve had gastric bypass, old rules of thumb about “one drink per hour” no longer apply to you.

Drug Interactions and Competing Pathways

Your liver doesn’t process alcohol in isolation. The same enzymatic pathways used to metabolize ethanol also handle a range of medications and other substances. When alcohol and a competing drug are present at the same time, they can slow each other’s clearance. This means that certain medications can effectively extend the time alcohol stays in your system, while alcohol can interfere with the metabolism of those drugs.

The interaction between ethanol and other substances that use the same metabolic pathways has long been recognized as clinically significant.¹⁶ Common examples include certain anti-anxiety medications, sleep aids, and some antibiotics, though the practical impact varies depending on the drug and the dose. The safest approach is to assume that any medication processed by the liver could interact with alcohol metabolism in either direction, and to ask a pharmacist about specific combinations rather than guessing.

Chronic heavy drinking adds another layer of complexity. Over time, the liver upregulates CYP2E1, a secondary alcohol-processing enzyme, which can actually increase the baseline rate of alcohol clearance. This is one reason heavy drinkers sometimes appear to “handle” alcohol better, since their livers have ramped up enzyme production. But that same upregulation also changes how other drugs are metabolized, which can make standard medication doses less effective or more toxic. And if heavy drinking eventually causes liver damage, the liver’s capacity to metabolize anything, alcohol included, declines.

Alcohol in Breast Milk

Alcohol passes freely into breast milk at concentrations that closely mirror blood alcohol levels. This means breast milk alcohol follows essentially the same timeline as blood alcohol: it rises after a drink, peaks when BAC peaks, and falls as the liver clears ethanol from the bloodstream. You don’t need to “pump and dump” to remove alcohol from milk; once your BAC drops, the milk alcohol level drops with it. Researchers have developed nomograms that estimate the time to zero alcohol in milk based on the amount consumed and the mother’s body weight.¹⁷

As a rough guide, a single standard drink clears from breast milk in about two to three hours for most women. Two drinks might take four to five hours. These estimates are conservative and vary with body weight, but they give a reasonable framework for timing nursing after drinking.

Congeners and the Hangover Timeline

Even after ethanol itself has cleared your system, you might still feel terrible. Hangovers involve dehydration, inflammation, disrupted sleep, and the lingering effects of acetaldehyde, but there’s also a contribution from congeners, the non-ethanol compounds produced during fermentation and aging. Darker spirits like bourbon contain far more congeners than clear spirits like vodka.

Experimental studies have confirmed that higher-congener beverages produce more severe hangover ratings than low-congener drinks, though the ethanol itself is by far the bigger driver of hangover severity.¹⁸ Interestingly, the same research found that performance impairment the morning after, things like reaction time and balance, was not significantly different between bourbon and vodka hangovers. So while congeners make you feel worse, they don’t appear to extend the period of functional impairment beyond what the alcohol itself causes.

The hangover timeline is worth distinguishing from the alcohol elimination timeline. Ethanol can be fully cleared from your blood while hangover symptoms persist for hours afterward. The two are related but not identical: the hangover reflects the cumulative metabolic disruption caused by the drinking episode, not the ongoing presence of alcohol.

Auto-Brewery Syndrome

In a handful of documented cases, people produce measurable blood alcohol levels without drinking. Auto-brewery syndrome is a rare condition in which gut microbes ferment carbohydrates into ethanol within the digestive tract.¹⁹ Patients can exhibit BAC levels high enough to cause intoxication after eating carbohydrate-rich meals, even with no alcohol consumption.

Recent research has identified specific bacteria responsible. Certain high-alcohol-producing strains of Klebsiella, including K. pneumoniae and closely related species, generated ethanol concentrations around 20 to 40 mmol/L in controlled experiments, both in living patients and in lab cultures.²⁰ A 2025 study using gut microbiome analysis confirmed that microbial ethanol metabolism is a genuine contributor to the syndrome in affected individuals.²¹

Auto-brewery syndrome is exceptionally uncommon, but it matters in forensic and legal contexts. Defendants have raised it in DUI cases, and the medical literature is slowly building enough evidence to distinguish genuine cases from manufactured defenses. For the typical person, endogenous alcohol production is negligible, contributing blood alcohol levels far below anything a test would flag. But for the rare individual with an overgrowth of the right microbes, the question of “how long does it take to get alcohol out of your body” takes on a dimension where the body is continuously producing what it’s trying to clear.