Drinking water between drinks helps mainly by slowing your pace and cutting how much alcohol you drink; if the total alcohol stays the same, water on its own makes little difference, and in the one trial that tested it, it made none. It's still worth doing, because the amount you drink is what matters most for the next morning.
Key takeaways
- In a 2026 randomized crossover trial, 13 men who drank extra water with sake had the same breath alcohol, psychomotor performance and next-day symptoms as when they drank sake alone.1
- In survey data reviewed by Utrecht researchers, water during or right after drinking had only a "modest" effect on next-day hangover, and water while hungover didn't change how people felt.2
- NIAAA says the more alcohol a person drinks, the worse the hangover will be.3
- A US standard drink contains 14 grams of alcohol, and many adults clear roughly one every one to two hours.4, 5
Why is drinking water between drinks common advice?
Because it makes intuitive sense twice over: alcohol makes you urinate more, and a popular theory holds that dehydration causes hangovers.3, 2 The researchers behind the 2026 trial note that the benefit of a water "chaser" has been "empirically recognized" but had not been verified.1
The dehydration theory is weak: dehydration effects after drinking are usually mild and short-lasting, and they don't track hangover severity.2 More in does alcohol dehydrate you?
What studies show
The one direct test found water alone didn't change the next day; surveys suggest a small benefit at most.
The trial. Japanese researchers had 13 healthy men drink sake containing 1.3 g of alcohol per kg of body weight, about six and a half US standard drinks for a 70-kg man, over one hour.1 On one occasion they also drank 15 mL of water per kg, about a liter, spread through the hour. The water made no difference to breath alcohol or acetaldehyde, to a psychomotor test, or to next-day symptoms such as headache, nausea and sleepiness.
It's small, all men with the fully active ALDH2 gene, and several authors worked for a beverage-alcohol company. But it's the only randomized test we found.
The surveys. A 2024 review by Utrecht University researchers summarized survey data: drinking water during or directly after alcohol had only a "modest" effect in preventing next-day hangover, and the amount of water drunk during a hangover wasn't related to changes in hangover severity or thirst.2 Surveys rely on memory and can't separate water from other habits.
The real benefit: pace and total drinks
Water helps when it replaces alcohol, not when it's added on top.
Total alcohol is the strongest lever you have. NIAAA says the more alcohol a person drinks, the worse the hangover.3 In a trial of beer and wine, perceived drunkenness and vomiting predicted hangover intensity, not drink type or order.6 And because your body clears alcohol at a fairly fixed pace, roughly one standard drink every one to two hours for many adults, a slower pace keeps less alcohol in your system at once.5
| Approach | Alcoholic drinks | Alcohol | What the evidence suggests |
|---|---|---|---|
| A drink every 45 minutes, no water | 4 | 56 g | The baseline |
| Same drinks, plus a glass of water with each | 4 | 56 g | Little or no next-day difference in studies |
| Alternate: one drink, then one water | 2 | 28 g | Half the alcohol; this is where the benefit comes from |
How much water is enough?
There's no tested amount. A glass of water for each alcoholic drink is an easy rule for pacing, and thirst is a reasonable guide beyond that.
MedlinePlus says there's no specific recommendation, and that drinking when thirsty and with meals keeps most people hydrated.7 Don't force it. With healthy kidneys, too much water almost never lowers blood sodium on its own, but Cleveland Clinic lists drinking too much beer or other alcohol among the causes of low blood sodium.8
Water before bed: helpful or not?
Helpful for thirst and a dry mouth, but not a hangover preventive. The surveys found only a modest effect of water directly after drinking.2 If you've vomited or sweated heavily, an oral rehydration drink replaces salt as well; see electrolytes for a hangover.
A glass of water is not a safety plan for someone who's very drunk. If a person is confused, vomiting repeatedly or hard to wake, call 911 rather than leaving them with water to sleep it off.9
A simple pacing system
- Eat first. Food slows alcohol absorption.5
- Pick a number before you go out. US guidance: "Consume less alcohol for better overall health." Pregnant women, people in recovery and people on interacting medicines shouldn't drink at all.10
- Count as you go in standard drinks. NIAAA suggests noting each drink before you drink it to help you slow down.11
- Alternate. One alcoholic drink, then one water, seltzer or soft drink.
- Set a last call; finish with water.
- Plan a ride home that isn't you driving. Hangovers impair attention and coordination the next day too.3
For the rest of the before-and-after plan, see how to prevent a hangover and how to drink responsibly.
What we don't know yet
- Whether water helps women, older adults or people with other ALDH2 variants differently; the only trial tested 13 men.
- How much of the survey benefit comes from water itself and how much from drinking less.
Frequently asked questions
Does drinking water before bed prevent a hangover?
Not reliably. Survey data show only a modest effect from water during or right after drinking, and a 2026 trial found extra water didn't change next-day symptoms. A glass before bed still helps with thirst and dry mouth.
How much water should I drink between alcoholic drinks?
There's no tested amount, but one glass of water per alcoholic drink is a simple pacing rule. The benefit comes mostly from drinking less alcohol, not from the water itself.
Does sparkling water count?
Yes, for pacing. Any non-alcoholic drink you sip between rounds slows you down. Plain sparkling water adds no sugar; soda and juice do.
Can you drink too much water while drinking alcohol?
It's uncommon for healthy adults, but very large amounts can dilute blood sodium, and heavy beer drinking is itself a listed cause of low sodium. Sip rather than chug. Confusion or seizures need emergency care.
Sources
- Imai H, Kushio S, Matsuura K, et al.. Water intake during drinking does not alleviate hangover symptoms. Front Pharmacol. 2026;17:1852528. PubMed
- Mackus M, Stock AK, Garssen J, Scholey A, Verster JC. Alcohol hangover versus dehydration revisited: the effect of drinking water to prevent or alleviate the alcohol hangover. Alcohol. 2024;121:9-18. PubMed
- National Institute on Alcohol Abuse and Alcoholism (NIAAA). Hangovers. Updated December 2025. niaaa.nih.gov
- NIAAA. What Is A Standard Drink?. Updated December 2025. niaaa.nih.gov
- Cederbaum AI. Alcohol metabolism. Clin Liver Dis. 2012;16(4):667-685. PubMed
- Köchling J, Geis B, Wirth S, Hensel KO. Grape or grain but never the twain? A randomized controlled multiarm matched-triplet crossover trial of beer and wine. Am J Clin Nutr. 2019;109(2):345-352. PubMed
- MedlinePlus (U.S. National Library of Medicine). Water in diet. Reviewed July 9, 2025. medlineplus.gov
- Cleveland Clinic. Hyponatremia. Health Library, updated November 27, 2024. my.clevelandclinic.org
- NIAAA. Understanding the Dangers of Alcohol Overdose. Updated December 2025. niaaa.nih.gov
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2025–2030. Released January 7, 2026. realfood.gov (PDF)
- NIAAA Rethinking Drinking. Tips to Try: Strategies for Cutting Down. Accessed October 9, 2026. rethinkingdrinking.niaaa.nih.gov
Published by Fuller Health, which makes After Party. This article is general information, not medical advice: talk to a doctor or pharmacist about your own health, medicines and drinking. Last reviewed October 9, 2026. How we research and write.