What's Actually In
Your Electrolyte

My wife bought two different electrolyte products recently. I had my own. We ended up with four different options in the kitchen and a conversation about which one was actually worth taking and when.

It's a question I get asked in clinic more often than you might expect — not just about electrolytes specifically, but about the broader category of supplement products that have moved from specialist health food shops onto supermarket shelves and into mainstream use. Most people are buying on marketing, flavour, or price. Very few are buying on formulation quality — because the information needed to assess formulation quality isn't on the label in any accessible form.

So this is that assessment. Four electrolyte products, looked at the way I look at any supplement: what's in it, at what dose, in what form, and for whom.

First — why electrolytes matter at all

Electrolytes are minerals that carry an electrical charge when dissolved in water. The major ones — sodium, potassium, magnesium, chloride, calcium, phosphorus — are not optional extras. They are the foundation of every biological process that requires electrical activity, which is most of them.

The sodium-potassium pump — an enzyme embedded in every cell membrane — maintains the electrochemical gradient that allows nerves to fire, muscles to contract, nutrients to enter cells, and waste to exit them. It consumes approximately 20–40% of the body's total ATP production at rest. Your brain alone uses one third of the body's ATP specifically to run sodium-potassium pumps. This is not a minor physiological process.

Magnesium is a cofactor in over 300 enzymatic reactions — including ATP synthesis itself. You cannot make energy without magnesium. Potassium regulates fluid balance inside cells, cardiac rhythm, and the membrane potential that determines nerve and muscle excitability. Sodium regulates fluid balance outside cells and is the primary determinant of blood volume and blood pressure.

These minerals are lost — rapidly and significantly — through sweat, urine, stress, and alcohol metabolism. The four scenarios where electrolyte replacement consistently produces subjective and objective benefit are:

Exercise and heat — sweat is not just water. It contains significant sodium (the dominant electrolyte in sweat — typically 0.9g per litre), potassium, magnesium, and chloride. Extended exercise or heat exposure without replacement produces hyponatraemia (low sodium), which drives headache, nausea, muscle cramps, and cognitive impairment. The popular advice to "drink more water" during exercise, without electrolyte replacement, can actually worsen hyponatraemia by diluting already-depleted sodium further.

Chronic stress — cortisol drives significant urinary excretion of magnesium and potassium. The chronically stressed person is almost certainly running a functional magnesium deficit — which impairs sleep, amplifies anxiety, drives muscle tension, and reduces stress resilience further. Electrolyte supplementation in this context is addressing a real deficit, not a marketing construction.

Alcohol — alcohol is a diuretic that drives urinary losses of sodium, potassium, magnesium, and zinc. Acetaldehyde — the toxic intermediate of alcohol metabolism — depletes glutathione and consumes zinc. The hangover is, in significant part, a combined dehydration and electrolyte depletion event. Replacing electrolytes before bed or first thing in the morning addresses the actual biochemistry rather than masking symptoms.

General insufficiency — the UK population is chronically magnesium insufficient. Soil depletion has reduced dietary magnesium content significantly over the past 50 years. Processed food diets provide essentially no magnesium. Stress depletes it further. Supplemental magnesium — in an adequate dose and absorbable form — addresses a genuine population-level gap.

The four products — clinical assessment

Side by side — the honest comparison

Which one for which scenario

A word on the "natural" electrolyte drinks

Coconut water deserves a mention because it occupies a specific position in the electrolyte conversation. It's genuinely high in potassium (approximately 600mg per 250ml), provides natural sugars for glycogen replenishment, and has a reasonable electrolyte profile for moderate exercise. The limitation is sodium — coconut water is very low in sodium, which makes it less effective for heavy sweat scenarios and can actually worsen the dilution problem if consumed in large quantities without sodium replacement.

For light activity and general hydration, coconut water is a reasonable whole-food option. For significant exercise or heat exposure, it needs sodium alongside it.

Sports drinks in general — Lucozade Sport, Gatorade, the mainstream options — are primarily sugar delivery systems with token electrolyte additions and artificial colours and sweeteners that have no place in a clinical nutrition framework. They were designed for elite athletes requiring rapid glycogen replenishment during extended competition, not for general hydration. Their marketing has dramatically outpaced their formulation quality.

The practical takeaway

You don't need all four products. What you need depends on your situation.

If you're doing serious exercise, managing chronic stress, or supporting recovery — Seeking Health is worth the cost for daily use. The formulation intelligence is genuine and the magnesium form alone justifies it over cheaper alternatives.

If you're buying for the whole family or want a budget daily option — Aldi is the honest choice. It does what it says, cleanly, without the marketing noise.

If you've been significantly depleted — illness, prolonged stress, post-surgical recovery, or a period of heavy training — Quinton Hypertonic addresses a different clinical need. It's not interchangeable with the others. It's mineral medicine.

If you already have Humantra — the chromium and vitamin C are genuinely useful. But when it runs out, the formulation quality of Seeking Health or even Aldi is a better use of your money.

And if someone tries to sell you a £4 protein water or a £5 CBD water and tells you it's the next evolution in functional hydration — come back and read this first.

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