The short version
- 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.
- On 19 October 2026 the six here ran from £5.35 to £16.49 a pack, which is 9.2p to 49.9p a tablet, and the cheapest pack is the dearest drink once you work it out per litre.
- 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.
Hydration tablets have stopped being a summer buy. The autumn and winter pull is different, and it is mostly stomach bugs, long-haul flights and the morning after, which is why the oral rehydration salts sit alongside the sports tubes on the same Amazon shelf. 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 Look Into made this guide: desk research, not a hands-on test. We shortlist on UK availability, compare published specifications and warranty terms, and read verified UK owner reviews, discounting incentivised ratings. Prices in the comparison table are pulled live from Amazon UK. Look Into has not handled these products: every figure comes from the maker, the listing or a named source, read on the date shown.
Prices in this table come from Amazon and are refreshed at least once a day, with the date of the last update under the table. The cost-per-use and running-cost figures on this page use prices Look Into read on 19 October 2026, so they can differ from today's price.
Compare live prices for every pick
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Prices and specs last checked by Look Into on 19 October 2026 · next check 14 December 2026 · how we picked
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 | Tablets per pack | Cost per tablet |
|---|---|---|---|
| SiS Hydro | Runners and gym | 60 (3 x 20) | 25.0p |
| HIGH5 ZERO | Everyday sipping | 60 | 26.8p |
| O.R.S Hydration | Travel and illness | 24 | 22.3p |
| Phizz 3-in-1 | All-rounder | 60 | 25.0p |
| Precision Hydration Electrolyte Capsules | Heavy sweaters | 15 capsules | 49.9p |
| WeightWorld Electrolyte Complex | Value and bulk | 180 | 9.2p |
Cost per tablet runs from 9.2p to 49.9p, a fivefold spread, and it is not the figure most people compare. The one that matters is cost per litre of made-up drink, and only two of the six listings state the water volume a tablet is meant for. SiS Hydro says 500 ml per tablet, which makes a litre 50.0p. O.R.S says two tablets in 200 ml, which makes a litre £2.23. So the cheapest tube on the shelf is the dearest drink by a factor of four, because it is an oral rehydration salt dosed for illness, and the sports tablets are dosed for sipping. For the other four, the listing gives no volume, so cost per litre cannot be worked out from the product page at all.
Corrected on 19 October 2026: this page previously called the Precision Hydration pick the PH 1000. Its Amazon listing no longer uses that name, so we have changed it to match the listing.
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
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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
As an Amazon Associate, Look Into earns from qualifying purchases. Product prices and availability are accurate as of 6 November 2026 1:13 pm and are subject to change.
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.
The catch: the taste is functional at best, and it is not designed for workouts.
24 tablets
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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
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Precision Hydration Electrolyte Capsules
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, with no flavoured drink, so casual users will likely find them overkill.
15 capsules
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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
As an Amazon Associate, Look Into earns from qualifying purchases. Product prices and availability are accurate as of 6 November 2026 1:13 pm and are subject to change.
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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