During-effort fuel · electrolyte · reviewed 28 Aug 2026
Precision Fuel & Hydration PH 500 25
250 mg of sodium per tablet is Precision's lightest hydration tablet, half of their own PH 1000 (500 mg) and a third of PH 1500 (750 mg), dissolved the same way in 16 fl oz of water so the dose scales down without changing how you drink it.
Score breakdown
The overall score is the average of what's below, each measured against every other electrolyte we've reviewed.
25
Weak
Sodium dose ?Sodium per serving, on a scale topping out at 1000 mg — a single dose covering the top of what's typically lost to sweat in an hour.25
Value (cost/1000mg Na) ?What it costs to get 1000 mg of sodium from this product. Not physiological -- a market-based scale from $3.00 (0) to $1.00 (100).0
Potassium ?Potassium per serving, on a scale topping out at 200 mg — roughly the upper end of typical hourly sweat loss.65
Calcium ?Calcium per serving. Weaker grounding than sodium/potassium -- sweat calcium loss is minor and not really a primary target during exercise; the 100 mg ceiling is this catalog's practical high end, not a physiological one.20
Magnesium ?Magnesium per serving, on a scale topping out at 60 mg, roughly matching cited hourly sweat-loss ranges.17
Cost per 1000mg sodium
$3.20/1000mg
Sodium per tablet
250mg
Comparison
6 of 11 electrolytes heldPrices per single sachet at the cheapest box size we track. Best in green, worst in red, across the gels shown.
| Measure | Precision Fuel & Hydration Precision Fuel & Hydration PH 500 | LMNT LMNT Citrus Salt | Nuun Nuun Sport | Precision Fuel & Hydration Precision Fuel & Hydration PH 1000 | Science in Sport SiS GO Hydro | 4Endurance 4Endurance Electrolytes |
|---|---|---|---|---|---|---|
| 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 | 250 mg |
| PotassiumWorks alongside sodium in muscle and nerve function. | 130 mg | 200 mg | 150 mg | 130 mg | 65 mg | 70 mg |
| CalciumInvolved in muscle contraction; lost in far smaller amounts than sodium. | 20 mg | 0 mg | 13 mg | 20 mg | 102 mg | 10 mg |
| MagnesiumSupports muscle and nerve function; some evidence it blunts cramping. | 10 mg | 60 mg | 25 mg | 10 mg | 8.1 mg | 50 mg |
| CarbohydrateMinimal by design. This is a hydration product, not a fuel source. | 3 g | 0 g | 4 g | 3 g | 0.9 g | 0 g |
| Price per tabletWhat one tablet costs. | $0.80 | $1.50 | $0.75 | $1.20 | $0.75 | $0.27 |
| Cost per 1000mg sodiumThe only price that compares across different sodium concentrations. | $3.20 | $1.50 | $2.50 | $2.40 | $2.17 | $1.08 |
Verdict
what it does · what it costsWhat it does well
- 250 mg sodium, 130 mg potassium, 20 mg calcium, and 10 mg magnesium per tablet, the fullest four-mineral breakdown of any tablet in this lineup
- Only 10 calories and 3 g of carbs per tablet, in line with GU Hydration Tabs' 10 calories and 3 g
- Same 15-tablet tube format and roughly $0.80/tablet price as Precision's other PH strengths, easy to mix and match doses
What it costs you
- At 250 mg sodium, under half of GU's 320 mg tablet; heavy sweaters will need two PH 500 tablets to match one GU tab
- Uses sucralose as a sweetener, unlike GU's stevia/cane sugar or Skratch's cane sugar/dextrose base
- The lightest option in its own range, so hot-weather or heavy-sweat sessions will likely need PH 1000 or PH 1500 instead
Where to buy
Prices and links as last checked.
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're a light-to-moderate sweater who wants Precision's dosing system without the higher-strength tablets
- You want a documented calcium and magnesium dose alongside sodium and potassium
Look elsewhere if
- You're a heavy sweater in hot conditions; PH 1000 or PH 1500 will match your losses with fewer tablets
- You're sensitive to sucralose and prefer stevia-sweetened tablets like GU's