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Ranked #10 · Best zero-calorie daily mix
Ultima Replenisher Review
Effectively a magnesium and potassium supplement with flavour — very little sodium, so judge it on that basis.
Last updated
- Sodium
- 55 mg
- Potassium
- 250 mg
- Magnesium
- 100 mg
- Sugar
- 0 g
- Format
- Powder stick
- Serving
- 1 stick pack (3.6 g)
- Mixes into
- 16 fl oz (475 ml)
- Third-party tested
- None publicly stated
The verdict
Buy it if
Everyday sipping, people who want magnesium and potassium without sodium, and anyone on a sodium-restricted diet.
Skip it if
You bought it expecting an athletic electrolyte drink — check the sodium figure first.
What's good
- Highest magnesium in this roundup at 100 mg
- Genuinely zero calories and zero sugar
- Plant-based colours and flavours, no artificial sweeteners
- Single-serve sticks travel well and need no measuring
What's not
- Only 55 mg sodium — this is not a sweat-replacement product and should not be sold as one
- Will not help with heat, endurance or acute dehydration
- Stevia flavour is polarising
Read the sodium figure before you buy
Ultima Replenisher carries 55 mg of sodium per serving. That is roughly one-eighteenth of what LMNT provides, and it is the single most important fact about this product.
It is sold with the same athletic visual language as everything else in the category, which is misleading. This is not a sweat-replacement drink and it will not help you through a hot long run. Judged on that basis it fails badly.
Judged as what it actually is — a zero-calorie magnesium and potassium supplement with flavour — it is a perfectly good product, and the stick packs remove the guesswork of scooping.
The highest magnesium in this roundup
At 100 mg, Ultima provides more magnesium than anything else here, alongside 250 mg of potassium and 65 mg of calcium. Both magnesium and potassium are nutrients that population intake data suggests people commonly fall short on, unlike sodium.
For someone who wants an easy way to add those to their day without calories, sugar or a large sodium load, that combination is genuinely well matched.
Who it is actively good for
Anyone on a sodium-restricted diet — for high blood pressure, heart failure or kidney disease — who still wants a flavoured electrolyte drink has very few options in this category. Ultima is one of the only mainstream products whose sodium content is low enough to be uncontroversial for that group.
If that describes you, still raise it with your clinician first, because potassium supplementation carries its own risks with impaired kidney function.
How it compares
Measured against the other 9 products we cover. Serving sizes differ across the category, so read these as positioning rather than a like-for-like ratio.
| Product | Sodium | Potassium | Sugar | Tested |
|---|---|---|---|---|
| Ultima Replenisher (this one) | 55 mg | 250 mg | 0 g | — |
| Cure Hydration | 240 mg | 300 mg | 4 g | — |
| Nuun Sport | 300 mg | 150 mg | 1 g | — |
| DripDrop ORS | 330 mg | 180 mg | 7 g | — |
What's actually in it
Per 1 stick pack (3.6 g), mixed into 16 fl oz (475 ml), as printed on the manufacturer's panel and checked on August 6, 2026.
| Serving size | 1 stick pack (3.6 g) |
|---|---|
| Mixes into | 16 fl oz (475 ml) |
| Sodium | 55 mg |
| Potassium | 250 mg |
| Magnesium | 100 mg |
| Calcium | 65 mg |
| Chloride | Not stated |
| Sugar | 0 g |
| Calories | 0 |
| Sweetener | Stevia leaf extract |
| Format | Powder stick |
| Third-party testing | None publicly stated |
Ultima Replenisher questions
Why is Ultima’s sodium so low?
Because it is formulated as a daily zero-calorie mineral supplement rather than a sweat-replacement drink. At 55 mg it is not intended to cover exercise losses, whatever the packaging imagery suggests.
Is Ultima good for athletes?
Not for replacing sweat. It provides useful magnesium and potassium, but a serious training session in heat needs many times its sodium content. Pair it with a higher-sodium product or choose one instead.
Is Ultima suitable on a low-sodium diet?
It is one of the few electrolyte mixes low enough in sodium to be plausible for someone restricting it. Because it also contains 250 mg of potassium, check with a clinician first if you have kidney disease or take potassium-sparing medication.
Where these numbers come from
Checked on August 6, 2026. Manufacturers reformulate without notice — verify the panel on the pack you receive.
Ultima Replenisher
Best zero-calorie daily mix
Other options worth comparing
- LMNT Zero Sugar Electrolytes, Raw Unflavoured — best overall for heavy or salty sweat.
- Redmond Re-Lyte Hydration — best balanced sodium-to-potassium ratio.
- Thorne Daily Electrolytes — best for drug-tested athletes.
Or go back to the full ranking of all 10.
Not medical advice. Electrolyte needs vary between individuals. If you have kidney, heart or blood-pressure conditions, or take medication affecting fluid balance, speak to a clinician before using this product regularly.