What Are Electrolyte Tablets? Benefits and Daily Use Guide

Electrolyte tablets have gone from something you'd find in a cyclist's back pocket to something people keep in their desk drawer. This guide explains what they are, what's in them, how they compare with water and sports drinks, and how to use them.

What are electrolyte tablets?

Electrolyte tablets are small tablets that you drop into water. Most are effervescent, so they fizz and dissolve in a minute or two, turning plain water into a lightly flavoured drink that contains minerals such as sodium, potassium, magnesium and chloride.

Those minerals are electrolytes. They help control fluid balance in your body and help your nerves and muscles work normally. You lose some every day in urine and sweat, and you replace them mainly through food.

What's in them

Formulas vary a lot between brands, so it's worth reading the label. The main differences are:

• Sodium. Sports formulas tend to be high in sodium, because that's the main electrolyte lost in sweat. Everyday formulas usually contain less.
• Potassium. Most UK adults get plenty of salt from food (an average of 8.4g a day against a 6g limit, according to the National Diet and Nutrition Survey) but less potassium than recommended, so some everyday formulas lead with potassium.
• Carbohydrate. Some contain sugar for energy during exercise. Others contain very little.
• Sweeteners and flavour. Low-calorie tablets usually use a sweetener such as sucralose or stevia.

Here's what a serving of HIRO electrolyte tablets (two tablets in about 300ml of water) provides, according to our label:

HIRO is sweetened with sucralose and is vegan. Potassium contributes to normal muscle function and normal functioning of the nervous system. Magnesium contributes to electrolyte balance and the reduction of tiredness and fatigue. HIRO is lower in sodium and higher in potassium than most sports drinks; our guide to high-potassium electrolyte tablets explains why.

Electrolyte tablets, water and sports drinks

Water is all most healthy adults need on an ordinary day, alongside a balanced diet. The NHS suggests 6 to 8 glasses of fluid a day.

Sports drinks are designed for long or intense exercise. They contain more sodium and a lot more sugar, which is useful two hours into a long run and less useful at a desk.

Electrolyte tablets sit in between. They add minerals and flavour to water with few calories, and a tube fits in a pocket. Many people find a flavoured drink easier to keep sipping than plain water.

Oral rehydration salts from a pharmacy are a different product again. They're designed for vomiting and diarrhoea, and that's when to use them. In a 2016 study comparing common drinks, oral rehydration solution was retained in the body better than water over the following hours, largely because of its sodium content.

When electrolyte tablets are useful

• After exercise, especially if you've been sweating a lot
• On hot days
• On flights and long journeys
• When you struggle to drink enough plain water
• As part of a morning routine, if that helps you drink more

They're an optional extra. If you're drinking enough and eating well, you don't need them.

How to use them

1. Drop two HIRO tablets into about 300ml of water.
2. Let them dissolve fully.
3. Drink it. Sip it over a meeting or a workout, or drink it straight down.

Don't exceed the serving on the label, and keep drinking plain water through the day as well.

Who should check first

Speak to your GP or pharmacist before using electrolyte products regularly if you have a kidney or heart condition, take medicines that affect potassium or sodium (including some blood pressure medicines), are pregnant or breastfeeding, or are an older adult. The NHS advises older people not to take potassium supplements unless a doctor recommends them. HIRO isn't recommended for anyone under 18.

Trying HIRO

HIRO comes in Lemon & Elderflower, Ginger & Lemongrass and Watermelon, and was voted Best Tasting Electrolyte Tablets by BBC Good Food in 2025. You can see every pack in our electrolyte tablets collection. The Multi-Flavour Triple Pack (30 servings, £24) lets you try all three. Subscriptions take 15% off, or 25% off if you choose delivery every three months, and delivery is free on orders of £30 or more. Every order is covered by our 60-day money-back guarantee. For cost per serving across every pack, see our electrolyte tablets price guide.

Frequently asked questions

Are electrolyte tablets better than water?

For most people on an ordinary day, water is enough. Electrolyte tablets can help after sweaty exercise, in hot weather or when you find it hard to drink enough plain water.

Can I take electrolyte tablets every day?

Most healthy adults can use an everyday formula daily as directed. Stick to the serving on the label and check with your GP or pharmacist if any of the conditions above apply to you.

Do electrolyte tablets contain sugar?

It depends on the brand. Sports formulas often contain a fair amount. A HIRO serving contains 5g carbohydrate and 20 kcal.