During-effort fuel · electrolyte · reviewed 28 Aug 2026
High5 Zero Electrolyte Tablets 41
56 mg of magnesium a tablet, more than any other tablet in this set, just short of LMNT's 60 mg stick dose, alongside 250 mg of sodium, the same figure as 4Endurance's tablet, at zero calories and zero sugar.
Score breakdown
Each dimension below is scored 0 to 100 against a fixed scale, not against the rest of the catalog, so adding a product never moves this number. The overall score is the average of the dimensions this product declares data for. How the scales are set →
Comparison
5 of 14 electrolytes heldPrices per single sachet at the cheapest box size we track. Best in green, worst in red, across the gels shown.
| Measure | High5 High5 Zero Electrolyte Tablets | LMNT LMNT Citrus Salt | Nuun Nuun Sport | Precision Fuel & Hydration Precision Fuel & Hydration PH 1000 | Science in Sport SiS GO Hydro |
|
|---|---|---|---|---|---|---|
| Overall scoreAn average of the various variables measured. | 41 | 75 | 37 | 36 | 44 | |
| SodiumThe main electrolyte lost in sweat, and the biggest single driver of cramping and hyponatremia risk. | 250 mg | 1000 mg | 300 mg | 500 mg | 345 mg | |
| PotassiumWorks alongside sodium in muscle and nerve function. | 70 mg | 200 mg | 150 mg | 130 mg | 65 mg | |
| CalciumInvolved in muscle contraction; lost in far smaller amounts than sodium. | 9 mg | 0 mg | 13 mg | 20 mg | 102 mg | |
| MagnesiumSupports muscle and nerve function; some evidence it blunts cramping. | 56 mg | 60 mg | 25 mg | 10 mg | 8.1 mg | |
| CarbohydrateMinimal by design. This is a hydration product, not a fuel source. | 0 g | 0 g | 4 g | 3 g | 0.9 g | |
| Price per tabletWhat one tablet costs. | $0.54 | $1.50 | $0.75 | $1.20 | $0.75 | |
| Cost per 1000mg sodiumThe only price that compares across different sodium concentrations. | $2.16 | $1.50 | $2.50 | $2.40 | $2.17 |
Verdict
what it does · what it costsWhat it does well
- 56 mg of magnesium, the highest of any tablet here (only LMNT's stick, at 60 mg, carries more).
- Zero calories and zero carbohydrate, with 28 mg of vitamin C included.
- Nine flavours in the range, more variety than any other electrolyte product here.
What it costs you
- 250 mg of sodium is well below LMNT's 1000 mg or Precision's 500 mg.
- Green tea extract is declared at 1 mg but not broken out as a caffeine dose, so the actual caffeine content can't be read off this label.
- Not sold through US retailers; pricing here is converted from GBP and availability will vary.
Where to buy
Prices and links as last checked. The price next to the name above is per unit at the cheapest box size we track; a single-unit price below may run higher.
Who this is for
the numbers, appliedThe field tells you what it is. This is who should act on it.
Worth the money if
- You want the highest magnesium dose of any tablet here without LMNT's full 1000 mg of sodium.
- You want a zero-calorie, zero-sugar tablet with vitamin C built in.
Look elsewhere if
- You're comparison-shopping strictly in US dollars; this line is priced in GBP with no confirmed US listing.
- You need a large single-tablet sodium dose; 250 mg is modest next to LMNT or Precision.