Best Electrolyte Supplements (2026)
When Do You Actually Need Electrolytes?
Water alone isn’t always enough. You lose sodium, potassium, and magnesium through sweat, and if you’re not replacing them, performance drops. You likely need electrolyte supplementation if you:
- Train hard for 60+ minutes, especially in warm environments
- Practice intermittent fasting, where you’re not getting electrolytes from food for extended periods
- Follow a low-carb or keto diet, which causes your kidneys to flush more sodium
- Sweat heavily — some people lose far more sodium than others
Sodium Content Comparison
Sodium is the primary electrolyte lost in sweat. Most people need 500–1500mg per session depending on intensity and sweat rate.
| Product | Sodium | Potassium | Magnesium | Sugar | Format | Price |
|---|---|---|---|---|---|---|
| LMNT | 1000mg | 200mg | 60mg | 0g | Sachets | £1.60/serving |
| SiS GO Hydro | 345mg | 65mg | 0mg | 0g | Tablets | £0.50/serving |
| Bulk Electrolyte Tabs | 250mg | 60mg | 20mg | 0g | Tablets | £0.20/serving |
| Myprotein Electrolyte Plus | 160mg | 100mg | 56mg | 0g | Tablets | £0.15/serving |
| Precision Hydration | 500–1500mg | Varies | Varies | 0g | Sachets | £1.20/serving |
1. LMNT — Best Overall
1000mg sodium per sachet puts LMNT in a league of its own. No sugar, no fillers, just electrolytes. The Citrus Salt and Watermelon Salt flavours are excellent. Premium priced but genuinely effective for heavy sweaters, fasters, and endurance athletes. This is what most sports drinks should be.
2. Science in Sport GO Hydro — Best for Endurance
Drop a tablet in 500ml water and you get a light, refreshing electrolyte drink. 345mg sodium is solid for moderate training. Widely used by cyclists and runners. The effervescent format is convenient for gym bottles. Berry and Lemon flavours are both pleasant.
3. Bulk Electrolyte Tablets — Best Budget
At 20p per serving, these are the cheapest option that actually works. 250mg sodium is moderate — fine for standard gym sessions. The effervescent format dissolves quickly. Lemon flavour is the best of a limited range.
4. Myprotein Electrolyte Plus — Best for Casual Use
Lower sodium (160mg) but includes a broader mineral profile with magnesium and potassium. Better suited for general hydration support than hardcore training. Cheapest per serving and available in most Myprotein orders as an add-on.
5. Precision Hydration — Best Personalised Option
Offers a sweat test to determine your personal sodium loss rate, then recommends a specific strength (500, 1000, or 1500mg sodium). Used by professional athletes across multiple sports. The sachets mix into a clean-tasting drink. Pricey, but the personalisation is unique.
DIY Electrolyte Drink
If you’re on a tight budget: 1/4 teaspoon salt (about 500mg sodium) + a squeeze of lemon in 500ml water. It works. It just doesn’t taste great.
The Bottom Line
LMNT for serious training and fasting. SiS for endurance sports. Bulk Tablets for budget-friendly daily use. Most gym-goers doing 45–60 minute sessions with a normal diet probably don’t need to supplement electrolytes at all — just drink water and eat food.
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