Alcohol makes you lose fluid, and fluid on its way out takes dissolved minerals with it — mainly sodium, potassium and magnesium. It happens because alcohol suppresses vasopressin, the hormone that tells your kidneys to hold onto water. Those losses are real and measurable. They are also only part of the story, and anyone telling you otherwise is selling something.
We are also selling something. So we will show our work.
Why alcohol makes you lose fluid in the first place
Your kidneys do not decide how much water to keep on their own. They take orders from vasopressin, a hormone released by the brain that tells them to reabsorb water rather than send it to your bladder.
Vasopressin (also called antidiuretic hormone, or ADH) is the signal that tells your kidneys to hold onto water instead of excreting it.
Alcohol suppresses that signal. With less vasopressin in circulation, your kidneys stop holding the line, and more water leaves than otherwise would. That is why the bathroom trips start early and keep going long after you would expect.
One detail most articles skip: the effect is front-loaded. In a 2024 review in Alcohol, the excess urine output was concentrated in roughly the first two hours of drinking, not spread evenly across the night.
Which electrolytes actually go
Electrolytes are minerals that carry an electrical charge when dissolved in water. Your body runs its nerve signals, muscle contractions and fluid balance on them. (The full explainer.)
When you lose fluid, you lose what was dissolved in it. Three minerals do most of the work, and all three go out the same door.
Sodium
The main electrolyte in the fluid outside your cells, and the one that governs how much water your body holds where. Sodium is why oral rehydration solutions taste faintly of salt rather than of nothing.
Potassium
Sodium's counterpart inside the cells. The two work as a pair to move signals along nerves and to trigger muscle contraction, and both leave in the fluid you are losing.
Magnesium
Involved in hundreds of enzyme reactions, including the ones that turn food into usable energy and let muscles relax after they contract. Magnesium is also the one plenty of people are already running low on before they drink anything at all.
Is dehydration what causes a hangover?
No — and this is where most articles on the subject overreach, so we are going to do the opposite.
The losses described above are real and worth putting back. They are not what makes the morning feel the way it does.
That same 2024 review found the fluid deficit after ordinary social drinking to be modest and quick to resolve, and no meaningful shortfall detectable during the morning-after state itself. Its authors describe hangover and fluid loss as things that travel together without one producing the other.
Which leaves the question of what does. The short answer is your immune response and your sleep, neither of which is a plumbing problem — and we have put the case for that somewhere it can be made properly rather than compressed into three sentences here.
Go deeper: Does water help a hangover? takes that argument apart in full.
Does an electrolyte drink put back what you lost?
Partly, and the honest version is more specific than the marketing version.
Yes for the minerals, which is what this article is about. The fluid is more conditional than the marketing implies: salt by itself turns out to be a poor lever, and what actually moves retention is salt arriving together with a small amount of sugar. Skip either half and you have an expensive glass of water.
That single fact is the most useful thing to know when comparing products, so it gets its own treatment rather than a footnote here.
Go deeper: What to look for in an electrolyte drink — the criterion, and how to read a label against it.
What actually helps
- Drink water through the night, not just after. Pacing beats catching up.
- Eat something. Food slows how fast alcohol is absorbed, and the carbohydrate is part of what helps fluid stay put.
- Put minerals in the water, not just water. A glass of plain water dilutes the sodium you have left rather than restoring it.
- Protect sleep where you can. Of everything on this list it has the best evidence behind it and gets the least attention.
- Give it time. Nothing you drink speeds up the metabolism already under way.
Frequently asked questions
Does alcohol dehydrate you? Yes, by suppressing vasopressin so your kidneys excrete more water than they otherwise would. The effect is real but, in the research, milder and shorter-lived than the popular explanation suggests.
Do electrolytes help a hangover? They replace minerals you measurably lost, which is worth doing on its own terms. They do not address the sleep debt or the inflammation, and on current evidence those are the larger part of why the morning feels the way it does.
Which electrolytes does alcohol deplete most? Sodium, potassium and magnesium — the three dissolved in the fluid you are losing. Magnesium is also the one many people are already low on before drinking.
Is coconut water a good electrolyte replacement after drinking? It is high in potassium but low in sodium, which is the mineral that matters most for holding onto fluid. It is a fine drink and an incomplete replacement.
Can I just drink a lot of water instead? You can, and you should drink water regardless. But water without minerals dilutes what sodium you have left, which is why oral rehydration formulas exist at all.
How long does it take to rebalance? Fluid and electrolytes come back quickly once you are drinking and eating normally. Sleep debt and inflammation run on a slower clock, which is usually what people are actually feeling.
What Snake Oil does here
Sodium, potassium and magnesium — the three minerals this article is about — plus 5g of carbohydrate so the sodium has something to travel with, alongside zinc, the B lineup, vitamins C and E, and a glutamine-led amino acid blend.† One stick in 16 ounces of water.
That is the mineral column of the ledger, in full, and only the mineral column. Sleep and inflammation are not on it.
Related reading: When should you take a recovery drink — before bed or the morning after? · Do hangovers get worse with age?
†These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.