Coffee or a cold shower sobers you up
Short answerNo
On this page
No. Coffee, a cold shower and a walk don’t lower the alcohol in your blood, and NIAAA says they don’t reverse the effects of an overdose. In a lab study, caffeine made people feel more alert after drinking but left them slower than sober. Only time clears it, at your liver’s fixed pace.
What we’d do
Don’t use coffee to sober up, for yourself or anyone else. It changes how drunk you feel and leaves how drunk you are where it was, and that gap is what gets people hurt. If you need to be clear by a certain time, the only thing that works is fewer drinks and an earlier last one. Don’t drive after drinking, however awake the coffee makes you feel.
If you remember three things
- Nothing you drink or do speeds up the liver. It clears about 15 mg per 100 mL of blood an hour on average, whatever else you do.
- Caffeine changes the feeling and leaves the level alone. In a lab study it helped one reaction test, but not balance or a second test, and people stayed slower than sober.
- Your level can keep rising after your last drink. Alcohol still in your stomach keeps entering the blood.
Why does it seem to work?
You do feel different. Coffee makes you more alert. A cold shower is a jolt. A walk in the night air wakes you up. Each one changes how you feel within minutes, and it’s natural to take that as the alcohol going away.
Coffee after drinks is like turning up the radio to cover a noise in your car’s engine. You notice the problem less, and it’s still there.
What does caffeine really do?
In a 2001 lab study, 15 adults took a capsule with no caffeine, 200 mg or 400 mg, then drank either no alcohol or 0.6 g of alcohol per kg of body weight. That’s about three US drinks for a 160 lb woman and three and a half for a 190 lb man. Forty-five minutes later they did a set of tests, including a driving simulator.
Alcohol alone made them feel dizzy and high, slowed their reactions and their braking, and made them sway more on their feet. Caffeine on its own made them feel alert and jittery. With both, caffeine sped up their braking a little, but it didn’t help their swaying or a choice reaction test, and their braking was still slower than when they were sober. The authors concluded caffeine “will not completely counteract alcohol impairment.”
Caffeine can make people feel more alert than their reactions really are, and that gap is where the danger is.
Why can’t anything speed it up?
Most of the alcohol you drink is cleared by one enzyme in your liver, and a 2010 review of the published rates found it works at a fixed pace once the first drink or two is in, about 15 mg per 100 mL an hour on average. Coffee doesn’t change that pace, a shower doesn’t, and walking doesn’t. NIAAA puts it directly: “cold showers, hot coffee, and walking do not reverse the effects of alcohol overdose and could actually make things worse.”
The only thing that measurably sped up clearing in the studies we use is food. In a 1994 lab study, men who drank right after breakfast cleared the same dose about two hours sooner, and a meal eaten five hours after drinking raised their clearing rate by 36 to 50%. That still takes hours.
On our engine, four US drinks at 7, 8, 9 and 10pm take a 190 lb man until about 2:40am to mostly clear, and a 160 lb woman until about 5:35am. No amount of coffee moves those times. How your body clears alcohol explains why.
Why can the level keep rising?
NIAAA warns that blood alcohol “can continue to rise even when a person stops drinking or is unconscious,” because alcohol in the stomach and intestine keeps entering the blood. Someone who has a few drinks fast and then switches to coffee can keep getting more drunk for a while, even as they feel more awake.
When it’s an emergency
Some people reach for coffee or a cold shower when a friend is very drunk. NIAAA says that’s the wrong move, and that it’s dangerous to assume someone will be fine sleeping it off. The critical signs are confusion, trouble staying awake or can’t be woken, vomiting, seizures, slow breathing (fewer than 8 breaths a minute) or long gaps between breaths, a slow heart rate, clammy skin, and a very low body temperature or bluish, pale skin.
If you see those signs, call 911 right away, and don’t wait for every symptom. Stay with the person, keep them sitting or partly upright on the ground, and if they’re lying down, roll them onto one side so they can’t choke.
The best case for coffee
“Caffeine really did help reaction time in that study.” It helped one test, braking, a little. It didn’t help balance or a second reaction test, and braking stayed slower than sober. A cup of coffee the next morning is fine. Using coffee to feel ready to go somewhere after drinking is the risky part, because the alcohol is still there.
Don’t drive after drinking. This site won’t tell you when you can.
Checked against NIAAA’s page on the dangers of alcohol overdose (updated December 2025) and the forensic review of clearing rates by Jones (2010), on November 14, 2026.
4 sources
- National Institute on Alcohol Abuse and Alcoholism, Understanding the Dangers of Alcohol Overdose, updated December 2025niaaa.nih.gov
- Liguori A, Robinson JH, Caffeine antagonism of alcohol-induced driving impairment, Drug and Alcohol Dependence, 2001pubmed.ncbi.nlm.nih.gov
- Jones AW, Evidence-based survey of the elimination rates of ethanol from blood with applications in forensic casework, Forensic Science International, 2010pubmed.ncbi.nlm.nih.gov
- Jones AW, Jönsson KA, Food-induced lowering of blood-ethanol profiles and increased rate of elimination immediately after a meal, Journal of Forensic Sciences, 1994pubmed.ncbi.nlm.nih.gov
