Part of our Asian Flush & Alcohol guide library.
Short answer: Your liver clears alcohol at a fairly steady rate, lowering blood alcohol concentration (BAC) by about 0.015 g/dL per hour on average in moderate drinkers. At that rate, a BAC of 0.08, the legal driving limit in most U.S. states, takes roughly 5 hours to return to zero. Alcohol itself is usually detectable in blood and breath for up to about a day, while a urine test for the alcohol byproduct ethyl glucuronide can detect drinking for up to about 90 hours. Coffee, cold showers and sleep do not speed this up.
Whether you are planning to drive the next morning or just wondering why you still feel off, it helps to know how your body handles alcohol. Here is how fast alcohol leaves your system, how long it can show up in breath, blood and urine, what changes the rate, and why there is no shortcut.
What you'll learn
- How fast your body clears alcohol, hour by hour
- How long alcohol shows up in breath, blood, urine and hair
- Why the rate differs between people
- Why coffee and sleep do not speed it up, and when to get help
How your body processes alcohol
After you drink, alcohol passes into your bloodstream, where it builds up until your liver breaks it down (NHTSA). The liver does most of the work, mainly through an enzyme called alcohol dehydrogenase (Jones, 2010). That process creates acetaldehyde, a toxic, short-lived byproduct (NIAAA). Because the enzyme is saturated after the first few drinks, your liver clears alcohol at a roughly constant rate rather than faster when there is more of it (Jones, 2010). That is why drinking more mostly means waiting longer.
How long does alcohol stay in your system?
A review of the forensic research found that BAC usually falls by 0.010 to 0.035 g/dL per hour, with 0.015 g/dL per hour a good average for moderate drinkers (Jones, 2010). Using that average, here is a rough illustration of how long it takes to get back to zero:
| Starting BAC | Approximate time to reach zero at 0.015 g/dL per hour |
|---|---|
| 0.04 | About 2.7 hours |
| 0.08 (legal driving limit in most states) | About 5.3 hours |
| 0.12 | About 8 hours |
| 0.16 | About 10.7 hours |
| 0.20 | About 13.3 hours |
This is simple arithmetic, not a prediction for you; your own rate may be faster or slower. Keep in mind that BAC can keep rising for a while after you stop drinking, because alcohol still in your stomach and intestine continues to enter the bloodstream (NIAAA). So the clock does not really start counting down at your last sip.
How long alcohol shows up on tests
Different tests look for different things, so the window varies:
| Test | What it measures | Typical detection window |
|---|---|---|
| Breath | Alcohol in your breath, which reflects your BAC (NHTSA) | Until BAC returns to zero, usually within about a day (Walsham & Sherwood, 2012) |
| Blood | Alcohol itself | Up to about a day (Walsham & Sherwood, 2012) |
| Urine (EtG test) | Ethyl glucuronide, a byproduct of alcohol | Up to about 90 hours (Walsham & Sherwood, 2012) |
| Hair | Ethyl glucuronide stored in hair | A much longer period, used to look at drinking over time (Crunelle et al., 2014) |
These are general ranges. How long a test stays positive also depends on how much you drank and on the test itself.
Why it differs from person to person
- Food: in studies, alcohol was cleared faster when people had eaten (about 0.015 to 0.020 g/dL per hour) than on an empty stomach (about 0.010 to 0.015) (Jones, 2010).
- Sex: the rate tends to be slightly faster in women, possibly because of differences in liver size relative to lean body mass (Jones, 2010). Sex also affects how high BAC rises in the first place (NIAAA).
- Heavy drinking: people with alcohol use disorder, measured during detox, cleared alcohol faster, about 0.025 to 0.035 g/dL per hour, because another liver enzyme becomes more active (Jones, 2010). This is not a protective effect.
- Age, tolerance, speed of drinking and medications all change how strongly alcohol affects you (NIAAA).
- Genes: if your face turns red when you drink, your body may be slow to clear acetaldehyde; see why some people get Asian flush.
Can you speed it up?
No. Your liver works at its own pace, and there is no way to speed up the brain's recovery from alcohol: coffee, a shower or a morning drink will not do it (NIAAA). Coffee may make you feel more awake, but it does not lower your BAC. Cold showers, hot coffee and walking also do not reverse an alcohol overdose and can make things worse (NIAAA). Drinking water, eating and sleeping are reasonable things to do, but the only thing that lowers BAC is time.
For the morning after, see how long a hangover lasts and what helps. Caffeine follows similar rules; see how long caffeine stays in your system.
Alcohol, driving and the next morning
It is illegal to drive with a BAC of 0.08 g/dL or higher in all 50 states, the District of Columbia and Puerto Rico, except Utah, where the limit is 0.05, and even small amounts of alcohol can affect driving ability (NHTSA). After a late night of heavy drinking, you may still be over the limit the next morning. If you have been drinking, plan another way home and give yourself plenty of time before driving.
When to get help
Mixing alcohol with opioids, sleep aids, anti-anxiety medicines such as benzodiazepines, or even over-the-counter antihistamines can be dangerous (NIAAA). Call 911 right away if someone who has been drinking is confused, cannot stay awake or be woken, is vomiting, has a seizure, has slow or irregular breathing, or has clammy, pale or bluish skin. Do not assume they will be fine sleeping it off (NIAAA).
A U.S. standard drink has about 14 grams of alcohol: 12 ounces of 5% beer, 5 ounces of 12% wine or 1.5 ounces of 40% spirits (NIAAA). Counting drinks this way makes it easier to know how much you have had.
Common myths (quick reality check)
Myth: Sleeping it off clears alcohol faster. Reality: Sleep does not speed up your liver. Only time lowers BAC, and it can even keep rising for a while after you stop drinking.
Myth: Coffee sobers you up. Reality: Coffee may make you feel more alert, but it does not lower blood alcohol. There is no way to speed up recovery.
Myth: If you feel fine, the alcohol is gone. Reality: You can feel normal and still have alcohol in your blood. Allow plenty of time before driving.
Frequently asked questions (FAQ)
How long does alcohol stay in your system?
Blood alcohol falls by about 0.015 g/dL per hour on average, so a BAC of 0.08 takes about 5 hours to reach zero. Alcohol is usually detectable in blood and breath for up to about a day.
How long does alcohol stay in your urine?
A urine test for ethyl glucuronide, a byproduct of alcohol, can detect drinking for up to about 90 hours.
How long does alcohol stay on your breath?
Breath alcohol reflects blood alcohol, so it lasts until your BAC returns to zero, usually within about a day.
How long does it take for one drink to leave your system?
It depends on how high your BAC rises, which varies by person. Once BAC peaks, it falls by about 0.015 g/dL per hour on average.
Can you flush alcohol out of your system?
No. Water, coffee, showers and exercise do not speed up how fast your liver clears alcohol. Only time lowers BAC.
Why do I still feel drunk the next morning?
After heavy drinking, BAC can take many hours to return to zero, so you may still have alcohol in your system. Do not drive until you are sure it has cleared.
Related guides
- How to sober up: what works and what doesn't
- How long does a hangover last?
- Why do Asians get Asian flush?
- Alcohol and liver disease
- How to prevent Asian flush
- How long does caffeine stay in your system?
Disclaimer and when to seek help
This article is for general education and is not medical or legal advice. These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease. Call 911 for signs of alcohol poisoning. Talk to your health care provider if you take medication, have liver disease, are pregnant or breastfeeding, or are concerned about your drinking.
References
- Jones AW. "Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework." Forensic Science International, 2010;200(1-3):1-20. doi:10.1016/j.forsciint.2010.02.021
- Walsham NE, Sherwood RA. "Ethyl glucuronide." Annals of Clinical Biochemistry, 2012;49(2):110-117. doi:10.1258/acb.2011.011115
- Crunelle CL, et al. "Hair ethyl glucuronide levels as a marker for alcohol use and abuse: a review of the current state of the art." Drug and Alcohol Dependence, 2014;134:1-11. doi:10.1016/j.drugalcdep.2013.10.008
- National Highway Traffic Safety Administration. "Drunk Driving".
- National Institute on Alcohol Abuse and Alcoholism. "Understanding the Dangers of Alcohol Overdose".
- National Institute on Alcohol Abuse and Alcoholism. "Hangovers".
- National Institute on Alcohol Abuse and Alcoholism. "What Is A Standard Drink?".
