The short answer: water helps, but it isn't a magic shield. Dehydration is one cause of a hangover, so hydrating reduces some symptoms — but water does nothing about acetaldehyde, congeners, inflammation, or lost sleep.
What water fixes
Alcohol is a diuretic, so you lose fluid and electrolytes as you drink. Replacing them eases the headache, dry mouth, and dizziness that come from dehydration. Alternating each drink with water, and having a glass before bed, genuinely helps.
What water can't fix
Hydration doesn't touch the toxic acetaldehyde your body produces, the congeners in darker drinks, the inflammatory response, or the wrecked sleep. That's why you can drink plenty of water and still feel rough. The full list of causes.
Pair hydration with the rest
Water is one lever. Add food, pacing, sleep, and enzyme support — sip a Gush before you start to help your body process the alcohol itself. The complete prevention guide.
Always drink responsibly. This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.