Water is the obvious starting point for dehydration, but it’s not always the most effective choice. Drinks that contain a combination of electrolytes, a small amount of sugar, and even protein can keep your body hydrated longer than plain water. The best option depends on how dehydrated you are and what caused it.
Why Some Drinks Hydrate Better Than Water
Your intestines don’t just passively soak up water. They rely on a specific transport system where sodium and glucose work together to pull water through the intestinal wall and into your bloodstream. When sodium and glucose arrive together, a transporter in the gut lining moves them into cells at a fixed 2:1 ratio, and water follows. This is the entire basis behind oral rehydration solutions and why a drink with some salt and sugar rehydrates you faster than water alone.
Researchers have developed something called a beverage hydration index, which measures how much fluid your body retains from a drink compared to water over several hours. Oral rehydration solutions, full-fat milk, and skim milk all score higher than plain water on this index. Drinks with both carbohydrates and electrolytes consistently outperform water at the two-hour and four-hour marks.
The Best Drinks for Rehydration
Oral Rehydration Solutions
These are the gold standard for treating dehydration from vomiting, diarrhea, or heavy sweating. Products like Pedialyte and Drip Drop are designed with the precise ratio of sodium, glucose, and water that maximizes intestinal absorption. They consistently rank at the top of hydration studies. For mild to moderate dehydration, clinical guidelines from major children’s hospitals still recommend oral rehydration as the first-line treatment over IV fluids.
You can also make a basic version at home using a World Health Organization recipe: mix half a teaspoon (3 grams) of salt and 2 tablespoons (30 grams) of sugar into just over 4 cups (about 1 liter) of clean water. It won’t taste great, but in a pinch, it works.
Milk
Milk is one of the most effective hydrating beverages available, which surprises most people. Both skim and full-fat milk outperform water and sports drinks in fluid retention studies. Several things explain this. Milk’s calorie and fat content slows gastric emptying, meaning it leaves your stomach gradually and gives your intestines more time to absorb fluid. Milk also contains natural electrolytes like sodium and potassium.
The protein in milk, particularly casein, appears to play a unique role. Casein coagulates in the stomach, which further slows digestion and keeps fluid in your system longer. Milk proteins may also stimulate your body’s antidiuretic hormone, the signal that tells your kidneys to hold onto water rather than producing urine. If you’re lactose intolerant, lactose-free milk shows similar rehydration benefits.
Sports Drinks
Standard sports drinks like Gatorade or Powerade contain electrolytes and carbohydrates, which makes them more hydrating than plain water during or after exercise. They work through the same sodium-glucose absorption mechanism as oral rehydration solutions, though their electrolyte concentrations are typically lower. They’re a reasonable choice for rehydration after sweating heavily, but for illness-related dehydration, an oral rehydration solution is more effective because it contains more sodium.
Coconut Water
Coconut water is naturally rich in potassium, with smaller amounts of sodium and manganese. Some evidence suggests it performs comparably to sports drinks for rehydration. However, it’s no more hydrating than plain water in controlled comparisons, according to Mayo Clinic. Its potassium content is high, but it’s relatively low in sodium, which is the more critical electrolyte for rehydration. It’s a fine option if you enjoy it, but it’s not superior to cheaper alternatives.
Plain Water
For everyday, mild dehydration (you forgot to drink enough, it’s hot outside, you have a mild headache), water is perfectly adequate. Most people don’t need a specialized beverage for routine hydration. Where water falls short is when dehydration is caused by illness with vomiting or diarrhea, or after prolonged intense exercise, because you’re losing electrolytes along with fluid and water alone doesn’t replace them.
What About Coffee and Tea?
Caffeine is technically a diuretic, meaning it increases urine production. But the fluid in a cup of coffee or tea more than compensates for the small diuretic effect at typical caffeine levels. Most research shows that caffeinated drinks do not cause a net fluid loss in people who drink them regularly. A cup of coffee still contributes to your daily fluid intake. That said, caffeinated drinks aren’t ideal as your primary rehydration tool when you’re already dehydrated, because even a mild increase in urine output works against you when you’re trying to recover a fluid deficit.
Foods That Help With Hydration
About 20% of most people’s daily water intake comes from food, and certain fruits and vegetables are remarkably water-dense. Cucumbers and iceberg lettuce lead the pack at 96% water. Celery, radishes, and watercress come in at 95%. Tomatoes and zucchini are 94% water, while watermelon, strawberries, broccoli, and bell peppers all hover around 92%.
Eating these foods won’t replace drinking fluids when you’re noticeably dehydrated, but they contribute meaningfully to your overall hydration throughout the day. Snacking on watermelon or cucumber slices alongside your fluids is a practical way to take in both water and the minerals your body needs.
What to Avoid When Dehydrated
Alcohol is the most counterproductive choice. It suppresses your body’s antidiuretic hormone, causing your kidneys to flush out more water than you’re taking in. Highly sweetened drinks like sodas and fruit juices can also work against you. Beverages with very high sugar concentrations slow gastric emptying in an unhelpful way and can draw water into the gut rather than absorbing it, sometimes worsening diarrhea.
Energy drinks are another poor choice during active dehydration. They combine high caffeine doses with large amounts of sugar, and the caffeine levels often exceed what you’d get in coffee, pushing past the threshold where the diuretic effect becomes meaningful.
Signs You Need More Than a Drink
Mild dehydration, the kind that causes thirst, darker urine, dry mouth, and a dull headache, responds well to oral fluids. You can manage this at home with any of the drinks above.
Moderate to severe dehydration is different. If you notice a rapid heart rate paired with low blood pressure, dizziness when standing, confusion, or very little urine output over several hours, oral fluids alone may not be enough. Moderate and severe cases often require IV fluids in an urgent care or emergency setting, because the gut simply can’t absorb fluid fast enough to catch up with the deficit. This is especially true for young children and older adults, who can dehydrate quickly from a stomach bug or heat exposure.
One practical note on timing: when rehydrating from illness, sipping small amounts frequently works better than gulping large volumes. A stomach irritated by vomiting or infection is more likely to tolerate 2 to 3 tablespoons of fluid every few minutes than a full glass at once.