Some products have been through decades of long runs without a single change to the recipe, and Hydrixir is one of them. The original energy drink from Overstims, a French brand based near Toulon, promises isotonic hydration with no acidity and no preservatives, for €1.46 a bottle. At RunMorph, we put the spec sheet up against feedback from hundreds of users and an independent comparison by a dietitian. Here's the full verdict.
Overstims Hydrixir Antioxydant review: France's heritage sports drink put to the test
7.3/10
- Benchmark gut comfort: neutral pH, no acidity, no preservatives.
- Lightly sweet taste, a favourite on long efforts (4.6/5 on i-Run).
- Magnesium at 46 % of NRV per bottle, rare at this level.
The bottom line in 3 sentences
Hydrixir Antioxydant is a French isotonic drink with 37 g of carbs and 280 mg of sodium per 600 ml bottle, built for efforts under 3 hours. Gut comfort is its real strength: neutral pH, no acidity, no preservatives or colourings, and a lightly sweet taste that users love. On the other hand, its carb load falls short of modern ultra standards (60 to 90 g/h), and the formula skips potassium and BCAAs entirely.
7.3
/ 10 · RunMorph overall score
Who is it for?Road or trail runners doing 1 to 3 hour sessions who want a drink that's easy on the stomach, lightly sweet and cheap enough for daily training.
Who should skip it?Ultra trail runners aiming for 80 to 90 g of carbs per hour on race day: the dose per bottle is too low without extra fuel.
Overstims Hydrixir Antioxydant: France's heritage sports drink against 2026 standards
Overstims has been making its products in France for more than forty years, and Hydrixir is the sports drink the whole range was built on. The brand's positioning is clear: an isotonic drink for endurance efforts, sold on tolerance (no acidity, neutral pH, no preservatives) rather than on how much it can pack in. For very long efforts, Overstims actually points you to Hydrixir Ultra, a separate product developed with François d'Haene.
The world around it has changed. Modern fuelling strategies for the marathon and ultra target 60 to 90 g of carbs per hour, and products like Maurten Drink Mix 320 (80 g of carbs per bottle) have reset the benchmark. Hydrixir is still at 37 g per 600 ml bottle. So the question isn't whether it's a good drink, it's what job it's still the right drink for.
RunMorph's advice. If your strategy relies on gels and you just want a drink that hydrates and replaces salt without turning your stomach, Hydrixir is an excellent pick. If you want to get your 80 g of carbs per hour from the bottle, look at Maurten Drink Mix 320 or the TA Energy isotonic drink instead.
© Overstims, official photo used for editorial purposes
Objective technical data: the spec sheet against the numbers
| Spec | Official Overstims spec sheet | Independent check |
|---|---|---|
| Format tested | 600 g tub, lemon lime flavour | 14 bottles of 600 ml per tub (40 to 42 g of powder per bottle) |
| Carbohydrates | 88 g / 100 g of powder, of which 48 g sugars | 37 g per 600 ml bottle (of which 20 g sugars): fine for under 3 h, low for modern ultra fuelling |
| Sodium | 660 to 720 mg / 100 g depending on flavour | 280 mg per bottle (lemon), about 470 mg/L: within the recommended 300 to 500 mg/L range |
| Magnesium | 415 mg / 100 g (111 % NRV) | 174 mg per bottle, 46 % of NRV: a real bonus, rare at this level |
| Vitamins | C, E, B6, B1 | 34 to 46 % of NRV per bottle, consistent with the antioxidant claim |
| Potassium / BCAAs | Not in the formula | Confirmed by a French dietitian's independent comparison: a structural weakness |
| Sugar blend | Dextrose + glucose syrup (55 % simple sugars) | Rated as room for improvement by the same comparison: no maltodextrin or fructose to smooth out absorption |
| What's left out | No preservatives, no colourings, no acidity, gluten < 20 mg/kg | In practice: once mixed, the drink has to be finished the same day |
| Price | €21.90 for 600 g; 3 kg doypack available | €1.46 per bottle from the tub, €0.93 from the 3 kg bag: among the cheapest on the market per litre |
Two takeaways. First: the tolerance promise holds up, the ingredient list (neutral pH, no acidity, natural flavourings) and user feedback point the same way. Second: on pure nutritional performance, the benchmark comparison by dietitian Nicolas Aubineau scores the formula 9.5/20 on intrinsic quality, with two clear criticisms, a sugar blend that could be better and no potassium or BCAAs, offset by a price per kilo below the average.
Taste and gut comfort: the real strength, with one split opinion you should know about
Users agree remarkably on one thing: how gentle it is. On the official Overstims store as on i-Run (4.6/5 average), the reviews keep using the same words: "not sickly", "not too sweet", "easy to mix", "no stomach issues" even after several hours. The lemon lime flavour tested here is the best seller and the best rated in the range, which has 7 to 8 flavours depending on the format (mint, red berries, peach tea, citrus cocktail, mango passion fruit, multifruit, mojito).
To be fair: the RunAgora aggregator shows a harsher average of 3.5/5 from 6 reviews for the same lemon lime flavour, with complaints about a taste that's too faint or watered down. That's the flip side of "not too sweet": if you're used to strongly flavoured drinks, Hydrixir may taste bland. It comes down to use: if sweet drinks sit badly with you on the run, it's a plus; if you like a punchy taste, try it before buying the 3 kg bag.
The catch: 37 g of carbs per bottle, below modern standards
Let's do the maths the brand doesn't do for you. At the recommended dose (42 g of powder per 600 ml bottle) and the suggested intake (500 to 750 ml per hour), you take in between 31 and 46 g of carbs per hour. For a 1 h 30 to 3 h run, that's exactly right. For a high intensity marathon or an ultra where you're targeting 60 to 90 g/h, it's half what you need, and you'll have to top up with gels, like the brand's own Coup de Fouet gel, or bars.
The second catch is a practical one: Overstims dropped the plastic scoop from its tubs (a deliberate eco choice), so you now measure with a tablespoon, 3 tablespoons per 600 ml. When you're refilling mid race, that's less convenient than a pre-dosed stick. And users of the 3 kg format report that the doypack doesn't seal properly since the packaging change: tip it into a jar if you're storing it for several weeks.
© Overstims, official photo used for editorial purposes
Who is it for?
Road runners, from 10K to half marathon
This is its ideal territory: one bottle an hour easily covers your needs, the gut comfort spares you heartburn during intervals, and the price per litre (€0.93 to €1.46 a bottle) means you can train with it every day without thinking twice. For the marathon, plan on adding gels to get above 60 g/h.
Trail runners on outings under 3 hours
Sodium at 470 mg/L and magnesium at 46 % of NRV per bottle make it a smart choice for hilly runs in the heat. The lightly sweet taste goes down well when your stomach starts shutting down late in the run. Beyond 3 h, the brand itself sends you to its Ultra range.
Athletes with a sensitive stomach
If you've already ditched an energy drink because of heartburn or nausea, Hydrixir is probably the safest bet on the French market: neutral pH, zero acidity, zero preservatives, natural flavourings. It's the product fragile stomachs end up sticking with.
Hydrixir vs Maurten Drink Mix 320 vs TA Energy Isotonic: the comparison
| Criterion | Overstims Hydrixir Antioxydant | Maurten Drink Mix 320 | TA Energy Isotonic Drink |
|---|---|---|---|
| Carbs per bottle | 37 g / 600 ml | 80 g / 500 ml | 35 g per serving |
| Sodium | 280 mg / 600 ml | about 250 mg / sachet | 706 mg electrolyte blend per serving |
| Technology | Classic isotonic, neutral pH | Hydrogel (encapsulation) | Maltodextrin + glucose/fructose + BCAAs |
| Extras | Magnesium 46 % NRV, vitamins C/E/B6/B1 | None | BCAAs 1000 mg |
| Price per bottle | €0.93 to €1.46 | about €3.65 | about €2.30 |
| Target use | Efforts < 3 h, daily training | High intensity marathon and ultra | Long training runs, races < 3-4 h |
The verdict here is simple. Maurten plays in a different league: over twice the carbs per bottle, more than twice the price, and hydrogel tech built for pure performance. TA Energy is the closest French rival, with a more complete formula (BCAAs, fructose) but a higher price. Hydrixir wins on tolerance, price and availability: you'll find it everywhere, from i-Run to pharmacies, and you can drink it without a second thought.
What Hydrixir does really well
- Benchmark gut comfort: neutral pH, no acidity, no preservatives.
- Lightly sweet taste, a favourite on long efforts (4.6/5 on i-Run).
- Magnesium at 46 % of NRV per bottle, rare at this level.
- €0.93 a bottle in the 3 kg format: unbeatable per litre.
- Made in France, 7 to 8 flavours, gluten free.
Its real limits
- 37 g of carbs per bottle: not enough for 60-90 g/h strategies.
- No potassium and no BCAAs in the formula.
- Dextrose + glucose syrup only: no maltodextrin or fructose.
- Measured by spoon (scoop removed), 3 kg doypack criticised for its seal.
- Mixed drink must be finished the same day (no preservatives).
How to fit it into your RunMorph training plan
At RunMorph, we tell you to test your nutrition in training, never on race day. Here's how: on the long runs of your RunMorph marathon plan, mix a 600 ml bottle at the official dose (3 tablespoons) and take one or two sips every 10 minutes from the first kilometres, without waiting until you're thirsty. Note in your log how your stomach feels at hour 2, that's where drinks separate.
During marathon weeks at a sustained pace, use Hydrixir as your fluid and electrolyte base, then add a gel every 45 minutes to reach 60 g of carbs per hour. In hot weather, its sodium content often means you can skip extra electrolyte tabs on runs under 2 h 30.
The RunMorph Coach's verdict
Hydrixir Antioxydant isn't the most modern drink on the market, and it doesn't pretend to be: it's a classic, honest isotonic, made in France, that bets everything on tolerance and price. Its 37 g of carbs per bottle make it a drink for efforts under 3 hours, or for strategies where gels do the heavy lifting on energy. Within that brief, it's one of the best French drinks on the market, and by far the cheapest to train with. For competitive ultras at 80 g/h, it won't be enough on its own. RunMorph score: 7.3/10.
Key takeaways for your training
- 37 g of carbs and 280 mg of sodium per 600 ml bottle: perfect under 3 h, not enough on its own for ultras.
- Outstanding gut comfort: neutral pH, no acidity, no preservatives, lightly sweet taste.
- Magnesium at 46 % of NRV per bottle, a real plus against cramps.
- €0.93 a bottle in the 3 kg doypack: the cheapest in this comparison, by a mile.
- Measure it by the spoon (scoop removed) and move the 3 kg doypack into an airtight jar.