This is WHY DOES ALCOHOL MAKE YOU FEEL SO BAD THE NEXT DAY?
Alcohol doesn't just leave you dehydrated. It affects your sleep, increases urine production, can disrupt blood sugar and gut function, and triggers inflammatory processes. That's why simply drinking a glass of water doesn't necessarily make you feel normal again.
Hydration really matters.
Alcohol suppresses vasopressin, a hormone that helps your kidneys retain water. Less vasopressin means more fluid leaves your body through urine. Along with that fluid, you lose electrolytes.
So when you wake up thirsty, headachy, flat and generally awful, replacing both fluid and electrolytes is key.
That's where electrolytes have a legitimate role. Not as a hangover cure.
As part of replenishing what you've lost.
A FEW THINGS WORTH TRYING
Drink water before bed and when you wake up. And here's one that's worth trying: have a properly dosed electrolyte drink before you go to sleep after drinking alcohol. ie 1000mg sodium, 200mg potassium, 60mg magnesium. (possibly speaking from experience) Alcohol increases fluid loss, and replacing both fluid and electrolytes before bed can make a noticeable difference to how you feel the next morning.
Eat something. Alcohol can affect appetite and blood glucose, and food gives your body some of the energy and nutrients it needs while it processes the alcohol.
Don't underestimate sleep. Alcohol may help you fall asleep faster, but it can seriously disrupt the quality and architecture of your sleep.
And give your body time. There isn't a magic drink that can undo alcohol consumption overnight. (it does make a massive difference though)
THE TAKEAWAY
A hangover isn't simply dehydration.
But dehydration is a key part of the story.
Water replaces fluid. Electrolytes help replace minerals lost alongside it. Your body still needs time to deal with everything else.