Reviewed by Sarah Law, Naturopathic Nutritionist
Electrolyte Buyer's Guide: How to Choose the Best Supplement for Hydration and Performance
The best electrolyte supplement supplies meaningful sodium (~400–600 mg) and potassium (~400–600 mg) in roughly a 1:1 ratio, plus an absorbable magnesium (~100–200 mg), with zero sugar and third-party-tested UK manufacture [1]. Hydration is balance, not just water — trace-only tablets and sugary “hydration” drinks do little. On these criteria, LLS Ultimate Electrolytes (~500 mg sodium, ~500 mg potassium, ~150 mg magnesium malate, zero sugar) is built to match.
- Replace what you lose in sweat: sodium, potassium and magnesium keep nerves firing, muscles contracting and water where it is needed [1].
- Balance beats volume: aim for ~1:1 sodium to potassium — sodium without potassium leaves you puffy but under-hydrated inside cells [3].
- Magnesium form matters: malate or glycinate (not oxide) supports ATP energy and muscle relaxation [2].
- Avoid: added sugar, artificial colours, and trace-only formulas (under ~100 mg sodium/potassium do little) [4].
The balanced, zero-sugar formula in this guide is our Ultimate Electrolytes: ~500 mg sodium, ~500 mg potassium, ~150 mg magnesium malate, UK-made and third-party tested.
View productWhy Electrolytes Matter (Water Is Only Half of Hydration)
Electrolytes — mainly sodium, potassium and magnesium — manage where water sits inside and outside your cells. When they drop, you can drink plenty and still be functionally dehydrated. Sodium maintains plasma volume and blood flow; potassium stabilises the membrane potential for nerve impulses and muscle contraction; magnesium is a cofactor for ATP-dependent reactions and supports muscle relaxation between contractions [1][2]. The body performs best when sodium and potassium are provided together, with an absorbable magnesium alongside.
What to Look For on the Label
- Sodium: ~400–600 mg per serving to replace sweat loss and support fluid retention [1].
- Potassium: ~400–600 mg to complement sodium and support intracellular hydration and neuromuscular function.
- Magnesium: ~100–200 mg from a bioavailable form (malate or glycinate) for energy and muscle relaxation [2].
- Zero sugar & clean flavour: sugar is unnecessary for daily hydration and can upset the stomach in training.
Forms Compared
| Form | Strengths | Limitations |
|---|---|---|
| Powder (recommended) | Meaningful doses, precise control, best value, easy mixing | Needs a bottle/water |
| Effervescent tablets | Convenient for travel | Often low sodium/potassium; acidity regulators & sweeteners |
| Capsules | Portable, tasteless | Many capsules needed to reach meaningful doses |
| Ready-to-drink | Grab-and-go | Frequently sugary and low in minerals — “flavoured water” |
For real hydration benefit, a well-dosed, sugar-free powder gives the best balance of control, comfort and cost.
“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 & Functional Practitioner
Why Magnesium Form Matters
Magnesium oxide is common but poorly absorbed and can upset digestion. Magnesium malate pairs magnesium with malic acid (from the Krebs cycle), supporting energy production with better tolerability — which is why a good electrolyte uses malate or glycinate, not oxide [2].
Quality, Testing & Value
Judge cost per serving, not tub price — a cheap tablet with under 100 mg sodium is poor value despite the low sticker. Look for UK manufacture under GMP and BRC, independent third-party testing for mineral content and heavy metals, and clear per-serving amounts [4].
Recommended in this guide
Electrolytes built on balance, not sugar
Ultimate Electrolytes
~500 mg sodium · ~500 mg potassium · ~150 mg magnesium malate · zero sugar
Vegan · naturally flavoured · UK GMP & BRC
✓ Balanced 1:1 sodium:potassium✓ Zero sugar✓ Third-party tested✓ UK GMP & BRC
Which should you choose?
Frequently Asked Questions
What is the best electrolyte supplement?
One with meaningful sodium (~400–600 mg) and potassium (~400–600 mg) in roughly a 1:1 ratio, plus absorbable magnesium (100–200 mg), zero sugar, and third-party-tested UK manufacture.
Do electrolytes help with fatigue?
Sodium and potassium support nerve and muscle function while magnesium supports ATP energy production, so balanced electrolytes can reduce tiredness and cramping during training, heat and fasting.
Is it safe to drink electrolytes every day?
Yes, when balanced and sugar-free. Daily use helps maintain hydration in training, hot weather and busy schedules — adjust servings to your sweat rate.
Do electrolytes break a fast?
Zero-calorie electrolytes do not break a fast and are commonly used during fasting to maintain mineral balance.
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. Learn more about Sarah.
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 has spent over a decade helping UK customers choose transparent, research-led formulations made to UK GMP and BRC standards. Learn more about Ben.
References
- Sawka MN, et al. American College of Sports Medicine position stand: exercise and fluid replacement. Med Sci Sports Exerc, 2007.
- Volpe SL. Magnesium and the athlete. Curr Sports Med Rep, 2015.
- Convertino VA, et al. ACSM position stand: exercise and fluid replacement. Med Sci Sports Exerc, 1996.
- Maughan RJ, Shirreffs SM. Dehydration and rehydration in competitive sport. Scand J Med Sci Sports, 2010.