Key takeaways
- Electrolyte tablets replace the sodium, potassium and magnesium you lose through heavy sweating, which is why searches climb every time the UK hits a heatwave.
- For a normal day at a desk, plain water does the job. Tablets earn their place around exercise, hot weather, travel and recovery from illness.
- Prices here run from about £6 for a tube of oral rehydration salts up to around £16 for a 60-tablet multivitamin-and-electrolyte tube.
- Sugar-free options like HIGH5 ZERO and SiS Hydro suit all-day sipping, while O.R.S is the one to keep in the cupboard for illness or a rough morning.
Britain is deep into another hot summer, and every time the temperature spikes the hydration aisle empties out. When you sweat you don’t just lose water, you lose salts, and topping those back up is what electrolyte tablets are for. They’ve jumped from a running-club niche to a mainstream buy, helped along by festival season, holidays and a steady run of “hydration” videos on social media. We’ve pulled together six of the best you can get on Amazon UK right now, each suited to a different job.
How we picked these
We compared products on the things that actually matter day to day: electrolyte content (sodium, potassium and magnesium), whether they carry sugar or calories, price per serving, how they taste and how fast they dissolve, and the specific job each one is built for. We leaned on NHS guidance on dehydration and the British Dietetic Association’s advice on hydration for the general points, then ranked products on those specs and their UK review scores. Every price is what we saw on Amazon UK on the day of writing and will move around.
At a glance
| Product | Best for | Format | Sugar | Around |
|---|---|---|---|---|
| SiS Hydro | Runners and gym | Effervescent tablet | Sugar-free | £15 |
| HIGH5 ZERO | Everyday sipping | Effervescent tablet | Sugar-free | £13 |
| O.R.S Hydration | Travel and illness | Effervescent tablet | Contains glucose | £6 |
| Phizz 3-in-1 | All-rounder | Effervescent tablet | Sugar-free | £16 |
| Precision PH 1000 | Heavy sweaters | Salt capsule | Sugar-free | £7 |
| WeightWorld Complex | Value and bulk | Swallow tablet | Sugar-free | £15 |
The best electrolyte tablets, reviewed
Science in Sport (SiS) Hydro
Best for runners and gym sessionsFour key electrolytes plus a few B vitamins, no sugar and no calories. It is built for people shifting a lot of sweat on a run or a long ride, and it dissolves quickly with a light citrus taste that most people get on with.
The catch: it is aimed squarely at sport, so if you only want something for a hot day at your desk you are paying for performance branding you may not need.
20 tablets per tube · around £15
Check price on Amazon →HIGH5 ZERO
Best for sugar-free everyday sippingZero calories, no sugar and a useful hit of vitamin C. Buy the multipack and it is cheap per tablet, and the flavours are mild enough to keep a bottle going all day.
The catch: the electrolyte dose sits on the lighter side, so if you sweat heavily during hard training you may want something stronger.
Multipack, several flavours · around £13
Check price on Amazon →O.R.S Hydration Tablets
Best for travel and illness recoveryThese are oral rehydration salts, the same idea a pharmacist points you to after a stomach bug or a day caught out in the heat. The balance of sodium and glucose helps your body actually hold onto the water rather than pass it straight through.
The catch: the taste is functional rather than pleasant, and it is not designed for workouts.
24 tablets · around £6
Check price on Amazon →Phizz 3-in-1
Best for an all-rounder that doubles as your vitaminsOne tablet covers electrolytes, a full multivitamin and hydration, so it stands in for your daily vits too. You get 60 per tube, which is good value, and it is a long-standing favourite with frequent flyers.
The catch: if you already take a separate multivitamin you will be doubling up on some nutrients, so check the labels.
60 tablets · around £16
Check price on Amazon →Precision Hydration PH 1000
Best for heavy sweaters and enduranceA high-sodium option for people who sweat buckets or cramp on long efforts. These come as blister-packed capsules that are waterproof, so they survive a race belt or a soggy pocket.
The catch: they are capsules you swallow with water rather than a flavoured drink, so casual users will likely find them overkill.
15 capsules · around £7
Check price on Amazon →WeightWorld Electrolyte Complex
Best for value and bulk buyingA big 180-tablet tub that works out very cheap per serving and covers the main minerals along with magnesium and calcium. Handy when a whole household is topping up during a hot spell.
The catch: these are plain swallow tablets with no flavour, so you miss the cold-drink feel that makes the fizzy ones nicer to use.
180 tablets · around £15
Check price on Amazon →FAQ
Do electrolyte tablets actually work?
Yes, for replacing salts lost through heavy sweating or illness. For a normal day at a desk, plain water is usually enough on its own.
Are they safe to take every day?
For most healthy adults, one serving a day is fine. If you are on a low-sodium diet or have kidney or heart problems, check with your GP before making it a habit.
Can you have too much?
You can. Piling on sodium is not helpful, so stick to the dose on the label and do not stack several servings a day without a real reason.
Tablets or powder sachets?
Tablets are easier to carry and dose one at a time. Powders can pack a bigger hit but are messier when you are out and about.
Sources
NHS: Dehydration
British Dietetic Association: Fluid (water and drinks)
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