Reviewed by Sarah Law, Dip CNM, Naturopathic Nutritionist. Updated 22 September 2026
The best electrolyte supplement is the one whose label survives five checks: meaningful sodium, meaningful potassium, an absorbable magnesium, no sugar, and a cost per serving you can actually work out. For most people in the UK that means a sugar-free powder giving roughly 400 to 600 mg of sodium and 400 to 600 mg of potassium per serving, plus 100 to 200 mg of magnesium from malate or glycinate rather than oxide [1]. On those five checks our own Ultimate Electrolytes gives 500 mg sodium, 500 mg potassium and 150 mg magnesium malate in a 30 serving tub, with no sugar, at 93p a serving at the price on the page today.
This guide is the checking method rather than a list of opinions. Below you will find the sweat maths that decides how much sodium you personally need, a cost table that turns tub prices into pence per serving, and two real UK labels compared side by side with the figures read off each brand's own product page on 22 September 2026. Prices and stock on our own product pages are live, and every Love Life order carries a 60 day money back guarantee, so the cost maths here is something you can check rather than take on trust.
- Sodium per serving. Under about 200 mg is a flavouring, not a replacement. You lose sodium in sweat faster than any other mineral [2].
- Potassium per serving. Potassium is the main mineral inside the cell and is the one most often cut to a token amount because it tastes bitter.
- Magnesium form and dose. Malate or glycinate at 100 to 200 mg. Magnesium oxide is cheap to include and poorly absorbed [5].
- Sugar and sweetener. Sugar is unnecessary for daily hydration and is the reason many sports drinks sit heavily during training.
- Servings per pack. Without this you cannot compare prices at all, and some packs make it deliberately hard to find.
The product measured against these checks
Ultimate Electrolytes, priced per serving
Ultimate Electrolytes
30 servings, 500 mg sodium, 500 mg potassium, 150 mg magnesium malate, no sugar
1 tub every month, which matches 30 servings at 1 a day. Skip or cancel anytime
Third-party testedMade in the UK under GMP and BRC certification60-day guaranteeSix flavours, including unflavoured
What makes the best electrolyte supplement in the UK?
A supplement earns the description when one serving replaces a meaningful share of what you actually lose, in forms your gut can absorb, without anything you did not ask for. In practice that is four numbers and one omission: sodium, potassium, magnesium, servings per pack, and no added sugar. Everything else on the front of the pack, the branding, the athlete photos, the word hydration in a serif font, tells you nothing.
The reason those three minerals dominate is simple physiology. Sodium is the main electrolyte in the fluid outside your cells and it is what holds drunk water in circulation rather than sending it straight to your bladder [1]. Potassium is the main electrolyte inside the cell, where it sets the membrane potential that lets nerves fire and muscles contract. Magnesium is a cofactor for the ATP-dependent reactions that release energy, and it contributes to normal muscle function and to the reduction of tiredness and fatigue [5]. Calcium and chloride matter too, but they are rarely the limiting factor in a UK diet.
This is why plain water can leave you flat. Drinking a litre of water after a heavy session dilutes the sodium already in your blood, and your kidneys respond by clearing the excess fluid. Add sodium to the drink and you retain more of it, which is the whole mechanism behind rehydration drinks [3]. Research on the beverage hydration index found that drinks containing sodium and some other solutes kept people in positive fluid balance for longer than still water did [4].
What good looks like in numbers
- Sodium, 400 to 600 mg per serving. Enough to matter after a sweaty hour, not so much that a daily serving dominates your salt intake.
- Potassium, 400 to 600 mg per serving. Roughly matching sodium for everyday use.
- Magnesium, 100 to 200 mg per serving, as malate, glycinate or citrate.
- Zero sugar, with flavour from natural flavourings and a non-nutritive sweetener such as steviol glycosides.
- Clear serving count and a full per-serving panel, not amounts per 100 g.
If you want the underlying science of why the first two numbers move together, we have written it up separately in Sodium and potassium, the twin minerals behind true hydration. If you are new to the subject entirely, start with What are electrolytes and come back here when you are ready to compare labels.
How much sodium do you actually lose?
Far more than most labels replace, and the amount varies about six-fold between people. Published sweat sodium concentrations in athletes run from roughly 10 to 90 mmol per litre, which is about 230 to 2,070 mg of sodium in every litre of sweat, and an individual's figure is fairly stable but very different from the next person's [2]. Sweat rates in exercise commonly sit between 0.5 and 2.0 litres an hour depending on intensity, heat and body size [1].
Put those two ranges together and you get the table below, which is the single most useful thing on this page. It assumes a middling sweat rate of 0.8 litres an hour and asks one question: how many servings of a 500 mg sodium product would match what you lost?
| If you are | Sweat sodium | Sodium lost in 1 hour at 0.8 L/h | 500 mg servings to match 1 hour | Over a 2 hour session |
|---|---|---|---|---|
| A light salt loser | 300 mg per litre | 240 mg | 0.5 | 1.0 serving |
| Average | 700 mg per litre | 560 mg | 1.1 | 2.2 servings |
| A salty sweater | 1,200 mg per litre | 960 mg | 1.9 | 3.8 servings |
| A very salty sweater | 1,800 mg per litre | 1,440 mg | 2.9 | 5.8 servings |
Two things fall out of that table. The first is that a single serving is a sensible daily habit, not a full replacement for a hard session in heat. If you are the salty sweater in row three, riding for two hours in August, one scoop is a quarter of what you lost. The second is that a product with 100 mg of sodium a serving is not in this conversation at all. It would take ten of them to cover that ride, which nobody does, and which is why the tablet in your gym bag has never made much difference.
The counterweight is dietary sodium. UK adults are advised to have no more than 6 g of salt a day, which is about 2.4 g of sodium, and the average intake already sits above that guideline. If you train lightly or not at all, one balanced serving a day is a reasonable habit. If you have high blood pressure, kidney problems, or you take medicines that affect potassium, this is a conversation for your GP or pharmacist rather than a blog.
"The biggest mistake I see is people drinking litres of plain water and wondering why they still feel flat. Without sodium and potassium to hold it in the right place, water just passes through. Balance is everything, and most shop-bought hydration drinks are mostly sugar."
Sarah Law, Naturopathic Nutritionist and Functional Practitioner
The sodium to potassium ratio, and why so many labels get it wrong
For everyday hydration, aim for roughly one part sodium to one part potassium. Sodium holds fluid outside the cell, potassium runs the inside, and sweat takes both. A drink heavy in sodium with almost no potassium can leave you feeling puffy rather than genuinely rehydrated, because you have topped up one compartment and not the other. A drink heavy in potassium with almost no sodium has the opposite problem: very little of what you drink stays where it is needed.
You will still find high sodium products aimed at endurance athletes, and for a four hour ride in heat that choice is defensible, since sodium losses dwarf potassium losses over that kind of duration [6]. For the other 95 per cent of use cases, gym sessions, warm offices, fasting days, travel, hangovers and hot weather, a balanced serving is the better default.
The reason so few products do this is taste. Potassium chloride is bitter and salty at a real dose, so the cheap route is to add a pinch, list it on the label, and let the customer assume it is a meaningful amount. Reading the mg rather than the ingredient list is the whole skill. Our own approach, which we cover in how pink Himalayan salt and magnesium malate work together, is to dose the potassium properly and fix the taste with natural flavouring and stevia instead.
Why the magnesium form matters
Magnesium oxide is the cheapest way to put a big number on a label and one of the poorest absorbed forms. Organic magnesium salts such as malate, glycinate and citrate are better tolerated and better absorbed than the oxide, which is why a well-built electrolyte uses one of them even though it costs more per milligram [5].
We use magnesium malate, which binds magnesium to malic acid, an intermediate in the Krebs cycle where your cells make ATP. It suits a daytime hydration product because it is gentle on the stomach and does not carry the drowsy reputation that magnesium glycinate has earned in the evening. Magnesium contributes to normal energy-yielding metabolism, to normal muscle function, and to the reduction of tiredness and fatigue, which is the set of authorised claims that actually matches what people want from an electrolyte drink.
If you want the longer version of that decision, we set it out in why we use magnesium malate. For evening use, a separate magnesium glycinate is the more sensible pairing, and plenty of customers run malate in the day and glycinate at night.
Powder, tablet, capsule or ready to drink?
Powder wins on dose and on cost per serving, tablets win on travel, and ready to drink almost always loses on both. The format itself is less important than the number of milligrams it can carry, and that is where the formats genuinely differ: an effervescent tablet has to fit its minerals around the disintegrating agents that make it fizz, so there is simply less room for sodium and potassium.
| Format | What it does well | What to check before buying |
|---|---|---|
| Powder in a tub | Room for a full dose, best cost per serving, you can use half a scoop on light days | Servings per tub, and whether the scoop size on the label matches the panel |
| Single-serve sachets | Portion control, easy to carry, good for travel and races | Cost per sachet, which is usually well above the same product in a tub |
| Effervescent tablets | Light, no scooping, fits a jersey pocket | Sodium per tablet, plus acidity regulators and sweeteners in the ingredient list |
| Capsules | Tasteless, useful if you dislike flavoured drinks | How many capsules make one real serving, which is often four or more |
| Ready to drink | Nothing to prepare | Sugar content and mineral amounts, since many are flavoured water at a premium price |
We make the powder case at more length in electrolytes versus sports drinks, which compares a proper electrolyte serving with what is in a standard bottle off the shelf.
What a serving actually costs
Tub price tells you nothing until you divide by servings. A £15 pack that holds 10 servings is dearer per serving than a £28 tub that holds 30. Here is our own product priced three ways, using the live prices on the product page on 22 September 2026, and taken all the way down to the cost of the minerals themselves.
| How you buy | Price | Cost per serving | Cost per gram of sodium | Cost per gram of magnesium |
|---|---|---|---|---|
| One tub, one-time | £27.95 for 30 servings | 93p | £1.86 | £6.21 |
| Subscribe and Save, one tub a month | £25.16 a tub | 84p | £1.68 | £5.59 |
| Three tubs delivered together | £22.36 a tub, £67.08 the delivery | 75p | £1.49 | £4.97 |
Run the same three sums on whatever you are comparing against and the picture usually resolves quickly. The cost per gram of sodium column is the one that exposes trace-mineral products, because a pack that looks cheap on the shelf can be five or ten times dearer per gram of the mineral you are buying it for.
Reading two real labels: a worked example
Criteria are easier to trust when someone applies them in public, so here are two UK electrolyte powders in the same price bracket, with every figure read from each brand's own product page on 22 September 2026. One of them is ours, which you should factor in when you read the conclusion.
| Per serving | Ultimate Electrolytes | Artah Cellular Hydration |
|---|---|---|
| Sodium | 500 mg | 40 mg |
| Potassium | 500 mg | 525 mg |
| Magnesium | 150 mg, as malate | 60 mg |
| Servings per pack | 30 | 30 |
| Pack price | £27.95 | £27.20 |
| Cost per serving | 93p | 91p |
| Added sugar | None | None |
Two well-made products, two pence apart per serving, and a twelve-fold difference in the mineral you lose fastest. That is the argument for reading labels rather than prices. If your reason for buying is replacing sweat, the sodium column decides it. If you specifically want potassium and magnesium with very little sodium, perhaps because your diet is already salty or you have been advised to watch your intake, the low sodium option is doing exactly what it was designed to do. Neither is wrong. They are answers to different questions, sold under the same word.
Formulas and prices change. These figures were read on 22 September 2026 from each brand's own product page and are worth re-checking before you buy.
Quality, testing and what a UK label should tell you
Beyond the numbers, the questions worth asking are where it was made, what was tested, and what happens if you do not get on with it. UK manufacture under GMP or BRC certification means the site works to audited standards for hygiene, traceability and record keeping. Third-party testing means someone outside the company has checked that what is on the label is in the tub.
- Where it is made. Ultimate Electrolytes is manufactured in the UK under GMP and BRC certification.
- What is tested. Every batch of incoming raw material is FTIR tested to confirm its chemical fingerprint, and finished products are lab tested before they leave the facility. Our testing procedures page sets out each stage.
- What is in it. Sodium from Himalayan pink salt, potassium from potassium chloride, magnesium from magnesium malate, citric acid, natural flavouring and steviol glycosides. Nothing else. The full breakdown is in our formula breakdown.
- What if you do not like it. Return the tub within 60 days for a full refund under our money back guarantee, which matters more than usual with a flavoured powder you have never tasted.
- Sweetener. We use steviol glycosides rather than sucralose or aspartame, and explain that choice in zero sugar electrolytes.
A note from Ben, founder of Love Life Supplements. We built this formula backwards from the sweat numbers rather than from a flavour brief. The expensive decisions were the potassium at 500 mg, which is hard to make taste good, and magnesium malate instead of oxide, which costs several times more per milligram of magnesium. Both of those are why the tub is £27.95 rather than £15. If that is not the trade you want to make, the table above at least tells you what you are giving up.
Which one should you choose?
Matching the product to the day is more useful than a single winner.
- Daily hydration, training and hot weather. One serving of a balanced powder such as Ultimate Electrolytes, taken in the morning or before your session. Our guide to how to take electrolytes covers timing.
- Long endurance sessions in heat. More than one serving, spread across the session, guided by the sweat table above rather than by thirst alone.
- Fasting, keto or a GLP-1 medication. Electrolytes matter more than usual when carbohydrate intake drops, because the kidneys clear sodium faster. See electrolytes on keto, fasting and Mounjaro.
- Tiredness that water does not shift. Worth reading electrolytes and fatigue and low electrolytes explained before assuming a supplement is the answer.
- Evening calm and sleep. A daytime malate and an evening magnesium glycinate is a practical split, and the two do not overlap in the way people expect.
- Training with creatine. The two mix in one bottle. The detail is in creatine and electrolytes.
Frequently asked questions
What is the best electrolyte supplement in the UK?
The best electrolyte supplement for most people is a sugar-free powder that gives meaningful sodium and potassium in one serving, around 400 to 600 mg of each, plus 100 to 200 mg of magnesium from an absorbable form such as malate or glycinate, made in the UK and third-party tested. Our Ultimate Electrolytes provides 500 mg sodium, 500 mg potassium and 150 mg magnesium malate in a 30 serving tub at 93p a serving. Trace-mineral tablets and sugary hydration drinks do not replace what you lose in sweat.
What should I look for on an electrolyte label?
Five things, in this order: the sodium in mg per serving, the potassium in mg per serving, the magnesium form and amount, added sugar, and the number of servings in the pack so you can work out the cost per serving. If a label lists a proprietary blend, or gives amounts per 100 g rather than per serving, you cannot compare it, which is usually the point.
What is the ideal sodium to potassium ratio for hydration?
Roughly one to one for everyday hydration and general training. Sodium holds fluid in the blood and the spaces between cells, potassium is the main mineral inside the cell, and sweat takes both. Endurance athletes working long hours in heat often need more sodium than potassium, which is why very high sodium products exist, but for daily use a balanced 500 mg and 500 mg serving covers most people.
Which potassium is best in an electrolyte supplement?
Potassium chloride and potassium citrate are both well absorbed, and the practical difference is taste and dose. Potassium chloride carries a salty, slightly bitter note, which is why some brands include only a token amount. We use potassium chloride and dose it at 500 mg a serving, then balance the taste with natural flavouring and stevia rather than cutting the mineral.
Are electrolyte tablets or powder better?
Powder is usually better value and better dosed. An effervescent tablet has to fit its minerals around the fizzing agents, so sodium is often in the low hundreds of milligrams, while a powder scoop can carry a full serving. Tablets win on travel convenience. Check the per-serving sodium on both before deciding, because the format matters less than the number on the label.
Is it safe to drink electrolytes every day?
For most healthy adults a balanced, sugar-free electrolyte drink is fine as a daily habit, and one serving a day is the usual pattern. Keep sodium intake in mind against the NHS guideline of no more than 6 g of salt a day, which is about 2.4 g of sodium. If you have high blood pressure or kidney problems, or you take medication that affects potassium, speak to your GP or pharmacist first. There is more detail in can you drink electrolytes every day.
Do electrolytes break a fast?
A zero-calorie electrolyte drink does not break a fast. Sodium, potassium and magnesium provide no energy, so they do not trigger an insulin response. Check the label for added sugar, maltodextrin or glucose, which do carry calories. Our formula is sweetened with steviol glycosides and contains no sugar.
Are all electrolytes the same?
No, and the gap between products is larger than the packaging suggests. Two 30 serving packs at almost the same price can differ more than tenfold in sodium per serving, as the label comparison above shows. The minerals themselves are the same chemistry wherever you buy them, so what you are choosing between is dose, form and cost per serving.
Do electrolytes help with fatigue?
Magnesium contributes to normal energy-yielding metabolism and to the reduction of tiredness and fatigue, and potassium contributes to normal muscle function and to the normal functioning of the nervous system. If you are short of fluid and minerals after sweating, replacing them is the part of feeling flat that a drink can address. If tiredness persists when you are well hydrated, it is worth investigating properly rather than adding supplements.
Related reading
- What are electrolytes? A beginner's guide to hydration, balance and energy
- How to take electrolytes for maximum hydration and energy
- Sodium and potassium: the twin minerals behind true hydration
- Ultimate Electrolytes formula breakdown: ingredients, dosage and science
- Electrolytes vs sports drinks: which is better for hydration and recovery?
- Can you drink electrolytes every day?
- Electrolytes for women: hydration, hormones and energy support
- Electrolytes on keto, fasting and Mounjaro
References
- Sawka MN et al. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 2007. PubMed
- Baker LB. Sweating rate and sweat sodium concentration in athletes: a review of methodology and intra/interindividual variability. Sports Med. 2017. PubMed
- Shirreffs SM, Armstrong LE, Cheuvront SN. Fluid and electrolyte needs for preparation and recovery from training and competition. J Sports Sci. 2004. PubMed
- Maughan RJ et al. A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index. Am J Clin Nutr. 2016. PubMed
- Volpe SL. Magnesium and the athlete. Curr Sports Med Rep. 2015. PubMed
- Maughan RJ, Shirreffs SM. Dehydration and rehydration in competitive sport. Scand J Med Sci Sports. 2010. PubMed
- Convertino VA et al. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 1996. PubMed
References checked against PubMed on 22 September 2026.
The short version: read the sodium and potassium in mg per serving, check the magnesium is not oxide, divide the pack price by the servings, and ignore everything on the front of the pack. If that leaves you with our tub, it is because those numbers are the ones we built it around.
About the reviewer, Sarah Law, Dip CNM
Sarah Law is a Certified Naturopathic Nutritionist and Functional Practitioner specialising in hormonal health, gut health, and evidence-based nutrition. She holds a Diploma in Naturopathic Nutrition from the College of Naturopathic Medicine (CNM, London) and is a Certified Functional Health Coach. Sarah combines naturopathic principles with modern functional nutrition science to help her clients make informed health decisions.
About the author, Ben Law
Ben Law is the founder of Love Life Supplements and host of the Optimised Health Show. A qualified Advanced Dietary Supplement Advisor and Primal Blueprint Certified Expert, he champions science-led, transparent formulations and UK manufacturing standards. Over the last decade he has helped thousands of UK customers optimise performance and recovery with formulations made to UK GMP and BRC standards.