Does Water Help a Hangover? What the Evidence Says

Water helps a little, but it will not cure a hangover. Alcohol is a genuine diuretic — it makes you lose more fluid than you take in — so rehydrating eases the thirst and dry-mouth part of the morning after. But recent research finds that hangover and dehydration are two co-occurring yet independent results of drinking, and drinking water did not meaningfully reduce overall hangover severity (Mackus et al., Alcohol, 2024). In short: water is worth drinking, but it treats a symptom, not the whole hangover.

Why alcohol dehydrates you

Alcohol suppresses vasopressin, the hormone that tells your kidneys to hold onto water. With that signal turned down, your kidneys send more water out as urine instead of reabsorbing it, so you lose fluid faster than you replace it. The effect is sizeable: research indicates that alcohol in a drink can trigger the body to eliminate several times more water than the drink itself contained. That fluid deficit is why thirst, dry mouth, and a parched morning feeling are such familiar parts of the next day.

The part water can't fix

Here is where the popular "just drink water" theory falls short. If dehydration were the whole story, replacing the lost fluid would resolve the hangover — and it doesn't. In the 2024 analysis, markers of dehydration were not strongly tied to how bad people's hangovers were, and water intake failed to alleviate the hangover itself (Mackus et al., 2024). The headache, fatigue, nausea, and general awfulness stem from other processes too — the body's inflammatory response, the toxic breakdown product acetaldehyde, disrupted sleep, and more — none of which a glass of water reverses.

Congeners: why the drink choice matters

Not all alcohol produces equal hangovers at the same dose. Darker drinks — whiskey, brandy, red wine — contain more congeners, the byproducts of fermentation and aging, and higher-congener drinks tend to produce worse hangovers than clearer ones at a matched amount of alcohol. So part of hangover severity is about what you drank, not just how dehydrated you got, which is another reason water alone can't carry the full load.

So is water pointless? No

Water still earns its place — it just isn't magic. Because alcohol drives real fluid loss, rehydrating relieves the thirst-and-dry-mouth portion of the morning and is simply good practice when your body is down fluid. The most useful move is timing: pacing water alongside your drinks and having a glass before bed keeps you from waking up in a deep fluid hole. It won't erase the hangover, but starting the day less dehydrated is still better than starting it more dehydrated.

The only sure prevention

The honest bottom line is that the reliable way to avoid a hangover is to drink less alcohol, or none. Everything else — water, food, sleep — softens edges rather than removing the cause. Moderation, a slower pace, and lighter-colored drinks lower your odds; water supports you but does not immunize you. Treat hydration as one helpful habit among several, not a cure that lets you out-drink the consequences.

Keep water easy the night and morning after

If you are going to pace with water and keep a glass by the bed, make it effortless. The NuRich 32 oz Insulated Water Bottle ($29.99) holds a full night's worth of cold water on the nightstand, and the NuRich 18 oz Insulated Water Bottle ($14.99) is an easy grab to carry through the evening. Fill one before you go out, keep sipping, and wake up a step ahead. Browse the full lineup at the NuRich collection.

The bottom line

Alcohol dehydrates you for real, so water helps with thirst and dry mouth — but the evidence shows dehydration and hangover are separate problems, and water doesn't cure the headache, nausea, and fatigue. Pace your fluids, favor lighter drinks, and remember that the only certain prevention is drinking less. Water is a smart supporting habit, not a hangover antidote.

This article is for general informational purposes only and is not medical advice. If you are concerned about your drinking or your health, please talk with a healthcare professional.

Sources: Mackus M et al. "Alcohol hangover versus dehydration revisited: The effect of drinking water to prevent or alleviate the alcohol hangover." Alcohol, 2024; "Effects of alcohol consumption on copeptin levels and sodium-water homeostasis." American Journal of Physiology-Renal Physiology, 2020.