The short answer
Hydratis is a pleasant effervescent tablet, low in sugar, rich in potassium and magnesium. But it is not the rehydration drink its marketing suggests: prepared as the brand directs, it provides 232 mg of sodium per litre, seven times less than the WHO oral rehydration solution and less than half the threshold set by Europe for talking about water absorption. At 0.50 EUR a tablet and at least two tablets a day, it comes to 30 EUR a month for a benefit that water and a normal diet already provide.
What a tablet contains
| Nutrient | Per tablet, in 250 ml | For 5 tablets, the maximum advised |
|---|---|---|
| Potassium | 150 mg | 750 mg |
| Chloride | 90 mg | 450 mg |
| Sodium | 58 mg | 290 mg |
| Magnesium | 32.5 mg | 162.5 mg |
| Zinc | 1 mg | 5 mg |
| Manganese | 0.2 mg | 1 mg |
What the brand does well
A simple, low-sugar formula
No colouring, no preservative, and less than 1% sugar in the glass according to the brand. For someone who drinks too little because water bores them, a low-sugar flavoured drink is a real help, and much better than a fizzy drink.
Potassium and magnesium in useful amounts
At five tablets, Hydratis provides 750 mg of potassium and 162.5 mg of magnesium, around 38% and 43% of the reference values. This is where the formula is most heavily dosed.
Satisfied customers
The brand scores 4.4 out of 5 on Trustpilot across 845 reviews, of which 258 in the last twelve months, with 82% five stars.
What you need to know before buying
Too little sodium to rehydrate
Hydratis presents itself as an alternative to oral rehydration solutions. But what makes a solution work is the pairing of sodium and glucose: the WHO sets it at 75 mmol of sodium per litre, or 1,725 mg. Hydratis, prepared at one tablet per 250 ml, provides 232 mg. European law only authorises the claim « improves water absorption during exercise » from 460 mg of sodium per litre and 80 kcal of carbohydrate. Hydratis reaches neither.
| Drink, prepared according to the brand | Sodium per litre | Price per litre |
|---|---|---|
| Hydratis, 4 tablets | 232 mg | 1.98 EUR |
| Waterdrop Microlyte, 2 cubes | 248 mg | 1.83 EUR |
| Waterdrop Microdrink, 2 cubes | 136 mg | 1.50 EUR |
| Threshold for the European water absorption claim | 460 to 1,150 mg | |
| Sweat of an athlete, on average | about 825 mg | |
| WHO oral rehydration solution | 1,725 mg |
In cases of gastroenteritis or diarrhoea, especially in a child, you should use the oral rehydration solutions sold in pharmacies, not Hydratis.
For long exercise, it does not make up for sweat
An endurance athlete loses on average about 1.2 g of sodium per hour in their sweat, according to data from 1,303 athletes. A litre of Hydratis gives back 232 mg. For a session of less than an hour, water is enough; for long, hot exercise, you need a much saltier sports drink, as our guide to hydration for athletes explains.
A high price for what it is
The tube of 20 tablets costs 9.90 EUR, and the packs of 4 and 6 tubes offer no discount: 39.60 and 59.40 EUR, exactly the unit price; only a 6-tube pack sold separately comes down to 56.46 EUR, 5% less. At the minimum dose of two tablets a day, a tube lasts ten days, or 29.70 EUR a month, and 74 EUR at five tablets. A magnesium-rich mineral water provides part of these minerals for far less, see our guide to magnesium-rich waters.
Marketing that goes too far
The page claims that the tablet helps to « enhance your skin by hydrating it from within » and that « 91% of users feel the effect », a figure taken from a study carried out with a distributor on 46 participants. Neither of these two sentences corresponds to an authorised health claim or to a published study. The product is offered « from age 3 »: for a young child, ask the paediatrician for advice, all the more so as the formula contains zinc and manganese.
Customer reviews
On Trustpilot, on 24/09/2026: 4.4 out of 5, 845 reviews, split into 82% five stars, 7% four, 4% three, 1% two and 6% one star. We did not find a recent reply from the brand to negative reviews.
Who it suits, in practice
Yes, possibly, if you drink too little and a flavour helps you drink, knowing that you are mostly paying for the flavour, the potassium and the magnesium.
No for rehydrating after a stomach bug: take a pharmacy rehydration solution. No for endurance: the sodium dose is too low. And to find out how much to drink, our guide to how much water to drink a day sets it out. We have also reviewed Waterdrop, its main competitor.
How we put this review together
We have not tested this product and we do not claim to. Prices and composition were taken on 24/09/2026 from the brand’s official website, then compared with references from the WHO, European law and studies on athletes’ sweat.
Our sources
- Official website hydratis.co, consulted on 24/09/2026: prices, dosage, nutritional values and ingredients.
- WHO and Unicef, reduced osmolarity oral rehydration solution: 75 mmol/L of sodium.
- Regulation (EU) No 432/2012, claim on carbohydrate-electrolyte solutions: 20 to 50 mmol/L of sodium, 80 to 350 kcal/L.
- Baker LB et al., J Sports Sci, 2016, PMID 26070030: sweat sodium in 506 athletes.
- Barnes KA et al., J Sports Sci, 2019, PMID 31230518: sodium losses per hour in 1,303 athletes.
- Trustpilot, hydratis.co page, consulted on 24/09/2026.