How Long Does Alcohol Stay in Your System?
Alcohol stays in the bloodstream for hours, but the traces alcohol leaves behind stay in urine for days, in blood for weeks and in hair for months, depending on which test is used.
The liver clears alcohol at a fairly steady pace set mainly by one enzyme. This page covers how that process works, how long each test type detects alcohol, and why sobering up and testing clean are different things.
Key Takeaways
- The liver lowers blood alcohol concentration (BAC) by about 0.015 per hour on average, within a normal range of 0.010 to 0.035 per hour, according to a 2010 review by A. W. Jones.
- Breath, blood and standard urine tests detect alcohol only while alcohol is still in the body, which is usually a matter of hours.
- SAMHSA lists about 1 to 3 days for urine EtG and EtS tests to return to normal after drinking stops, and 2 to 4 weeks for the PEth blood test.
- Cold showers, hot coffee and walking do not reverse the effects of an alcohol overdose, according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA).
- Slow breathing under 8 breaths a minute, seizures, confusion or being unable to wake up are signs of alcohol poisoning and need a 911 call.
If you need help now
For a medical emergency, including a suspected overdose or a withdrawal seizure, call 911.
For a mental health or suicide crisis, the 988 Suicide and Crisis Lifeline is free, confidential and available 24 hours a day. Call 988, text 988, or chat online at 988lifeline.org. Spanish-language support is available by calling 988 and pressing 2 or by texting AYUDA to 988. Deaf and hard of hearing callers can connect through ASL by using the videophone option at 988lifeline.org.
Substance use disorders are treatable conditions. Most people who receive treatment improve, and returning to use after a period of abstinence is a common part of the course of the illness rather than a sign that treatment has failed.
How does the body metabolize alcohol?
The body metabolizes alcohol mainly in the liver. The enzyme alcohol dehydrogenase (ADH) turns alcohol into acetaldehyde, and a second enzyme, aldehyde dehydrogenase (ALDH), turns acetaldehyde into acetate. Acetate then leaves the liver and is broken down in other tissues.
The body handles alcohol differently from the way the body handles food. The body stores spare food energy as fat or sugar, but the body does not store alcohol. Alcohol stays dissolved in body water until the liver clears the alcohol, as pharmacologist Arthur Cederbaum of Mount Sinai School of Medicine explains in his 2012 review in Clinics in Liver Disease.
3 steps the liver uses to clear alcohol:
- Alcohol dehydrogenase (ADH) converts alcohol into acetaldehyde.
- Aldehyde dehydrogenase (ALDH) converts acetaldehyde into acetate, and the liver keeps acetaldehyde at low levels under normal conditions.
- Acetate leaves the liver and travels to other tissues, where the body breaks acetate down further.
Breath tests rely on the lungs. Alcohol in the blood passes into the air deep in the lungs, and Cederbaum puts the blood-to-breath ratio at about 2,100 to 1. A breath reading therefore tracks the alcohol level in the blood.
Alcohol from each drink passes mainly through this liver pathway, and alcohol-related damage to that same organ is known as alcoholic liver disease (ALD).
How fast the liver finishes this work sets the elimination rate, which decides how long blood alcohol stays up.
How fast does alcohol leave the bloodstream?
Alcohol leaves the bloodstream at an average of about 0.015 percentage points of blood alcohol concentration (BAC) per hour. The normal range runs from 0.010 to 0.035 per hour, so two people with the same reading clear alcohol at different speeds.
Forensic toxicologist A. W. Jones set out that range in a 2010 review in Forensic Science International, after screening a large number of peer-reviewed drinking studies. Jones found 0.015 per hour a good average for moderate drinkers. For drivers stopped by police, 0.019 per hour fitted better, because many of those drivers drink heavily.
How long does it take to sober up?
Sobering up takes as long as the liver needs to bring BAC from its peak to zero, which at the average rate is roughly 1 hour for every 0.015 of BAC. The clock starts at the peak, not at the last drink. NIAAA notes that BAC keeps rising after drinking stops, because alcohol still in the stomach and intestine keeps entering the blood. The table applies the Jones average and range to three peak readings. The figures are arithmetic on those rates, not a prediction for any one person.
| Peak BAC | Time to reach zero at the average rate (0.015 per hour) | Time across the normal range (0.035 to 0.010 per hour) |
|---|---|---|
| 0.05 | About 3.5 hours | About 1.5 to 5 hours |
| 0.08 | About 5.5 hours | About 2.5 to 8 hours |
| 0.15 | About 10 hours | About 4.5 to 15 hours |
Forensic scientists estimate blood alcohol with the Widmark equation, which is commonly used in forensic and legal work such as road-traffic cases, according to a 2019 review by Maskell and colleagues in Forensic Science International. The Widmark equation depends on a personal value called the rho-factor, which reflects how much body water the alcohol spreads into. Scientists estimate that body water from a person's sex, age, height and weight.
4 factors that change how high BAC rises or how fast BAC falls:
- Food: a meal slows alcohol absorption, and Jones found elimination ran at 0.015 to 0.020 per hour after eating, against 0.010 to 0.015 per hour on an empty stomach.
- Sex: women reach a higher peak BAC than men from the same dose for their weight, because women on average carry more body fat and less body water.
- Body water: a person with more body water spreads the same amount of alcohol more thinly, which is the difference the Widmark rho-factor captures.
- Long-term heavy drinking: people with alcohol use disorder (AUD) going through detox can clear 0.025 to 0.035 per hour, because a second liver enzyme, CYP2E1, becomes more active.
A falling BAC is only one part of the detection picture, because each type of test looks for something different.
How long can each type of test detect alcohol?
Breath, blood and standard urine tests detect alcohol only while alcohol is still in the body, usually for hours. Urine tests for ethyl glucuronide (EtG) detect drinking for 1 to 3 days, the PEth blood test for 2 to 4 weeks, and hair tests for months.
The difference comes down to what each test looks for. Breath and blood tests measure alcohol itself, and alcohol disappears as the liver works. Other tests measure direct markers made from alcohol, which the body clears more slowly, according to the Substance Abuse and Mental Health Services Administration (SAMHSA) 2012 advisory on alcohol biomarkers.
| Test | What it measures | Typical window |
|---|---|---|
| Breath | Alcohol in air from deep in the lungs, which tracks blood alcohol | While alcohol is in the blood, usually hours |
| Blood alcohol | Alcohol itself | While alcohol is in the blood, usually hours |
| Standard urine alcohol | Alcohol itself | While alcohol is in the body, usually hours |
| Urine EtG and EtS | Two breakdown products made from alcohol | About 1 to 3 days |
| Blood PEth | Phosphatidylethanol, a direct blood marker made from alcohol | About 2 to 4 weeks |
| Hair EtG | EtG stored in the 3 to 6 cm of hair nearest the scalp | Months, with no fixed day count |
How long does alcohol stay on your breath?
Alcohol stays on the breath for as long as alcohol stays in the blood, because breath alcohol mirrors blood alcohol at the 2,100 to 1 ratio Cederbaum describes. At the average rate, a breath test reading of 0.08 falls to zero in about 5.5 hours.
How long does alcohol stay in urine on an EtG test?
An EtG urine test measures ethyl glucuronide, a small breakdown product the body makes from alcohol. SAMHSA groups ethyl sulfate (EtS), a second breakdown product, with EtG. SAMHSA's 2012 advisory lists about 1 to 3 days for EtG and EtS to return to normal after drinking stops.
The EtG result depends on the lab's cutoff, measured in nanograms per milliliter (ng/mL). 3 EtG result bands SAMHSA describes:
- A high positive, above 1,000 ng/mL, is consistent with heavy drinking that day or the day or two before, or light drinking the same day.
- A low positive, 500 to 1,000 ng/mL, is consistent with heavy drinking in the previous 1 to 3 days, light drinking in the past 24 hours, or heavy exposure from another alcohol source.
- A very low positive, 100 to 500 ng/mL, is consistent with heavy drinking 1 to 3 days earlier, light drinking 12 to 36 hours earlier, or exposure from another alcohol source.
How long does a PEth blood test detect alcohol?
A PEth blood test measures phosphatidylethanol, which SAMHSA describes as a direct blood marker of alcohol. SAMHSA's advisory lists 2 to 4 weeks for PEth to return to normal after drinking stops. SAMHSA reported PEth staying in blood for as long as 3 weeks after only a few days of drinking about four drinks a day.
In 2012 SAMHSA called a PEth test promising and noted that little research on PEth existed yet.
How long does alcohol show up in a hair test?
A hair test measures EtG stored in hair as the hair grows. The Society of Hair Testing's 2019 consensus applies its cutoffs to the 3 to 6 cm of hair closest to the scalp.
Under that consensus, hair EtG above 5 picograms per milligram (pg/mg) strongly suggests repeated drinking. Hair EtG at 30 pg/mg or more strongly suggests chronic excessive drinking. The consensus defines chronic excessive drinking as 60 grams or more of pure alcohol a day over several months, roughly four standard drinks of 14 grams each.
The same consensus warns that bleaching, dyeing or perming can change hair EtG levels. SAMHSA describes the hair window as possibly too long, or not defined well enough, for most applied purposes.
A detection window is not the same thing as being sober, and that distinction is the next question.
Why are sobering up and testing clean not the same thing?
Sobering up means blood alcohol has fallen back to zero, which takes hours. Testing clean means the breakdown products have also dropped below a lab's cutoff, which takes days for EtG and weeks for PEth. A person can be sober and still test positive.
Cederbaum's review notes that EtG stays detectable in body fluids, sweat and hair after alcohol itself has left the body. That lag explains why a urine EtG test can come back positive on a morning when a breath test reads zero.
Driving law runs on blood alcohol, not on breakdown products. The National Highway Traffic Safety Administration (NHTSA) states that driving with a BAC of 0.08 or higher is illegal in all 50 states, except Utah, where the limit is 0.05.
Feeling awake the next morning does not mean BAC has reached zero. At the average rate, a BAC of 0.20 at midnight would still be about 0.095 at 7 in the morning, above the 0.08 limit.
Montana uses the 0.08 limit, so a Montana driver at 0.08 or higher is breaking Montana DUI laws.
EtG tests also pick up alcohol from sources other than drinks. SAMHSA's advisory warns that hand sanitizers and mouthwash contain alcohol and raise EtG levels enough to create false positives.
Because the liver sets the pace of elimination, the next question is whether anything speeds the liver up.
Can anything make alcohol leave the body faster?
No quick fix makes alcohol leave faster. The liver enzyme ADH is saturated, meaning working at full capacity, after the first few drinks, so blood alcohol falls at a steady rate. Cold showers, hot coffee and walking do not reverse an alcohol overdose, according to NIAAA.
Jones's 2010 review describes the falling phase of blood alcohol as zero-order, meaning the liver removes a fixed amount per hour. Cederbaum adds that the body has little hormonal control over the pace of alcohol elimination. Together those findings explain why no home remedy changes the pace of elimination.
Common misconception
Coffee, a cold shower or a brisk walk sobers a person up.
What the evidence shows. NIAAA states that cold showers, hot coffee and walking do not reverse the effects of alcohol overdose and could make things worse. Blood alcohol falls only as fast as the liver's saturated ADH enzyme allows (NIAAA, Understanding the Dangers of Alcohol Overdose, 2025; Jones, Forensic Science International, 2010).
Sleep carries its own danger after heavy drinking. NIAAA states that BAC can keep rising after a person stops drinking or passes out, because alcohol in the stomach and intestine keeps entering the blood. NIAAA calls it dangerous to assume that an unconscious person will be fine sleeping it off.
When blood alcohol climbs too high, the result is alcohol poisoning, which has clear warning signs.
What are the signs of alcohol poisoning?
The signs of alcohol poisoning are confusion, trouble staying conscious, vomiting, seizures, slow or irregular breathing, a slow heart rate, clammy or bluish skin, dulled reflexes and a very low body temperature. NIAAA advises calling 911 immediately, without waiting for every sign.
Medical emergency
Alcohol poisoning is a medical emergency, and a person who has passed out from drinking can die. If someone who has been drinking shows any of the signs below, call 911 now. Do not wait for every sign to appear, and do not leave the person alone.
NIAAA uses the term alcohol overdose for alcohol poisoning. An alcohol overdose happens when so much alcohol reaches the bloodstream that the brain areas controlling breathing, heart rate and temperature begin to shut down.
10 danger signs of alcohol overdose that NIAAA lists:
- Mental confusion or stupor, a state of being barely responsive
- Difficulty staying conscious, or being unable to wake up
- Vomiting
- Seizures
- Slow breathing, with fewer than 8 breaths a minute
- Irregular breathing, with 10 seconds or more between breaths
- Slow heart rate
- Clammy skin
- Dulled responses, such as no gag reflex, the reflex that prevents choking
- Extremely low body temperature, bluish skin color or paleness
NIAAA advises keeping an intoxicated person from being left alone, because the person is at risk of injury from falling or choking. NIAAA also advises rolling an unconscious person onto one side, with an ear toward the ground, to prevent choking.
Mixing alcohol with opioids or with sedatives, such as sleep and anti-anxiety medications, raises the risk of an overdose, according to NIAAA.
A poisoning scare, a failed test or a morning-after reading often raises a harder question about drinking itself.
When does a question about testing point to a drinking problem?
A test result shows recent drinking, not a diagnosis of alcohol use disorder (AUD). SAMHSA states that alcohol biomarkers are not a substitute for a person's own account and should not serve as the sole screening tool.
A drinking problem shows up in the signs and effects of alcohol addiction, which a single lab result does not measure.
Medical warning
A person who drinks heavily every day should not stop suddenly without medical advice. Alcohol withdrawal can bring seizures, delirium tremens and death. If someone in withdrawal has a seizure or becomes confused, call 911.
Stopping carries a different risk from drinking. Schwebach and Vempati, writing for emergency medicine training in 2023, describe alcohol withdrawal presenting with anxiety, a racing heart, seizures and delirium tremens, and the authors list death as a possible outcome. Clinicians rate withdrawal severity with the Clinical Institute Withdrawal Assessment for Alcohol (CIWA), a scale developed in 1989.
The order and timing of those withdrawal symptoms after the last drink make up the timeline of alcohol withdrawal.
For someone whose drinking has moved past questions of timing and testing, medically supervised detox manages the withdrawal risk, and structured treatment addresses the drinking itself.
New Frontier Recovery Center provides medically supervised detox at ASAM Level 3.7 and residential treatment at ASAM Level 3.5 for adults with alcohol use disorder in Huntley, Montana.
About this page
New Frontier Recovery Center publishes this material for general education. It does not replace assessment by a licensed clinician.
Frequently asked questions
How long does it take for alcohol to fully be out of your body?
Does drinking water flush out alcohol?
Can you still be drunk 7 hours later?
Is 12 hours enough to clear alcohol?
How long can a pee test detect alcohol?
Will 2 hours of sleep sober you up?
How many days can a PEth test detect alcohol?
Sources
- Jones, A. W. (2010). Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework, Forensic Science International, 200(1-3), 1-20. Elimination range of 10 to 35 mg/100 mL per hour, the 15 and 19 averages, the effect of food, faster clearance in detox, and zero-order kinetics.
- Cederbaum, A. I. (2012). Alcohol metabolism, Clinics in Liver Disease, 16(4), 667-685. The ADH and ALDH pathway, absorption and food, sex differences in peak BAC, the 2,100 to 1 breath ratio, and EtG persistence.
- Maskell, P. D., Jones, A. W., Savage, A. and Scott-Ham, M. (2019). Evidence based survey of the distribution volume of ethanol: comparison of empirically determined values with anthropometric measures, Forensic Science International, 294, 124-131. The Widmark equation and the rho-factor.
- Substance Abuse and Mental Health Services Administration (2012). The Role of Biomarkers in the Treatment of Alcohol Use Disorders, 2012 Revision, Advisory, 11(2). EtG, EtS and PEth windows, EtG cutoff bands, false positives from sanitizer and mouthwash, and the limits of biomarkers.
- Society of Hair Testing (2019). 2019 Consensus for the use of alcohol markers in hair for supporting the assessment of abstinence and chronic alcohol consumption. Hair EtG cutoffs of 5 and 30 pg/mg on a 3 to 6 cm segment.
- National Institute on Alcohol Abuse and Alcoholism (2025). Understanding the Dangers of Alcohol Overdose, fact sheet, updated December 2025. Overdose signs, the 911 instruction, rising BAC after the last drink, the standard drink, and the coffee and cold-shower myth.
- National Highway Traffic Safety Administration. Drunk Driving. The 0.08 BAC limit in all 50 states except Utah, where the limit is 0.05.
- Schwebach, C. and Vempati, A. (2023). Alcohol Withdrawal with Delirium Tremens, Journal of Education and Teaching in Emergency Medicine, 8(3), S1-S33. Withdrawal presentation and the CIWA scale.