Supplements
Do You Actually Need Electrolyte Drinks?
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed August 20266 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
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Most people in the UK do not need daily electrolyte sachets. The government advises 6 to 8 glasses of fluid a day, and the average adult already eats 8.4g of salt against a 6g maximum. Sachets earn their place during illness, long hot sessions, and heavy sweating.
Find the test that measures your magnesium →You wake up flat. Your calves cramp at night. By four in the afternoon your head aches and the water you have been drinking all day has not touched it. Somebody on a podcast says you are low on electrolytes, and a sachet is now on its way to your door.
1. Why is everyone drinking electrolytes?
Because it is the loudest supplement category of the year. The Rising Trends 2026 supplement report puts electrolyte drink mixes at roughly 60,500 monthly searches, up almost twentyfold on the year before. Sachets went from an endurance-sport item to a kitchen cupboard staple in about two summers.
The marketing story is simple and quite persuasive. Water alone “dilutes” you. Salt is not the villain you were told. Add the missing minerals back and the fog lifts.
Some of that holds up. Some of it does not. The useful question is not whether electrolytes matter, because they plainly do. It is whether you personally are short of them.
2. What is actually in a sachet?
Three minerals do most of the work, and one of them dominates the label. Electrolytes are simply minerals that carry an electrical charge in your body fluids. They move water in and out of cells and help nerves and muscles fire.
| MINERAL | WHAT IT DOES | TYPICAL UK SHORTFALL |
|---|---|---|
| Sodium | Holds fluid in the right compartments; lost in sweat | Rare. Most UK adults eat well above the maximum |
| Potassium | Works with sodium inside cells; supports normal muscle function | Common in low-vegetable diets, though usually mild |
| Magnesium | Contributes to normal muscle function and to reduction of tiredness | The one most often genuinely low, and it is measurable |
Notice the mismatch. A typical sachet leads on sodium, often 500mg to 1,000mg per serving. That is the mineral you are least likely to be short of.
“Adults should have no more than 6g of salt a day (around 1 level teaspoon).”
The England Sodium Survey measured what people actually eat using 24-hour urine collection. Mean intake came out at 8.4g of salt a day, about 40% above that maximum. Adding a sachet on top of an ordinary British diet is not correcting a gap.
3. When do electrolyte drinks earn their place?
There are real situations where replacing salt and fluid together beats water on its own:
- Vomiting or diarrhoea, where fluid and salts leave fast.
- Exercise past about 90 minutes, especially in heat.
- Heavy sweating at work, in a hot kitchen or on a building site.
- A day of visible salt crusting on your skin or kit.
For the illness case, the NHS points to a specific product rather than a lifestyle sachet. Oral rehydration solutions are dosed to treat fluid loss, and the NHS says a pharmacist can recommend one. Ask for that, not a flavoured hydration mix.
Outside those windows, the NHS Eatwell Guide is the baseline: 6 to 8 cups or glasses of fluid a day. Water, lower-fat milk, and tea and coffee all count towards it.
4. What if it is not a hydration problem?
This is the part the sachet cannot answer. Cramps, headaches and afternoon flatness are broad symptoms. Low electrolytes are one possible thread among several.
Take cramp, the symptom that sells the most sachets. A 2020 Cochrane review of 11 trials and 735 people concluded that magnesium is unlikely to give older adults a meaningful reduction in cramps. That is an honest finding, not a reason to ignore magnesium. It just means guessing is a poor strategy.
Our guide on blood tests for muscle cramps walks through the full list. Tiredness has its own overlapping set, and a full blood count is often where that trail starts.
There is also the other direction. Your kidneys are what actually hold your fluid and salt balance steady. If they are not keeping up, more salty drinks is the wrong response. That is what a urea and electrolytes test exists to look at.
5. What can you measure before you subscribe?
Start with the honest limits. Sodium and potassium are not measured in any Helvy panel. If you think you have a genuine sodium or potassium problem, that belongs with your GP, who can run a full U&E through the NHS.
What we do measure is the rest of the picture. Magnesium sits in our General Energy & Wellness panel (£149), alongside urea, creatinine, thyroid, vitamin D and B12. It is also in the Vitamins & Minerals panel (£159) next to the full iron workup.
For kidney handling of fluid and salt, the Thyroid & Vital Organs panel (£159) adds eGFR to urea and creatinine. Our kidney function guide explains what those three numbers describe together.
The sequence worth following: measure first, then decide what the sachet is for. Our magnesium blood test guide covers how that marker is read, and the energy and fatigue hub covers the markers people check alongside it.
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Your results come back with what each marker measures, where your number sits, and what it means in context. Read by a qualified clinician.
Frequently asked questions
Do I need an electrolyte drink every day?
For most people in the UK, no. The government advises 6 to 8 cups or glasses of fluid a day, and the average adult already eats 8.4g of salt against a 6g maximum. Daily sachets mainly make sense if you sweat heavily for a living or train long in heat.
Are electrolyte sachets bad for you?
For a healthy adult, an occasional sachet is unlikely to matter. The thing to watch is the running total. A 1,000mg sodium serving is roughly 2.5g of salt, so a daily habit can push you further past the 6g maximum. If you have high blood pressure or a kidney condition, ask your GP first.
Will electrolytes stop my night cramps?
Possibly not. A 2020 Cochrane review found magnesium unlikely to give older adults a meaningful reduction in cramps. Cramps often have no single cause, so it is worth checking what is measurable rather than assuming the answer is salt.
Can a blood test check my electrolytes?
Partly. Sodium and potassium are not in any Helvy panel, so a suspected problem with either belongs with your GP. Magnesium, urea and creatinine are measured, and eGFR sits in the Thyroid and Vital Organs panel.
What should I use when I have a stomach bug?
An oral rehydration solution rather than a lifestyle sachet. The NHS says a pharmacist can recommend one. These are powders you mix with water, and they are dosed for fluid loss rather than flavour.
Is plain water enough for a gym session?
For a typical hour in an air-conditioned gym, yes. Sodium losses over that length of session are small, and a normal meal afterwards replaces them. The picture changes past about 90 minutes, or in real heat.
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