Authentic Nutrition is a French brand born in the Chambéry area. It wasn't in our catalog yet, despite a solid reputation among field testers and a quality podium awarded by an independent dietitian. Its Booster+ isotonic drink has one clear goal: digestibility above everything else. We went through the available French reviews to see whether that promise holds up over time.
© Authentic Nutrition, official photo used for editorial purposes
Authentic Nutrition's Booster+ is a French isotonic energy drink, low in sugar, enriched with BCAAs and electrolytes, and designed to keep stomach trouble to an absolute minimum during exercise. It took first place in an independent comparison of 44 energy drinks run by sports dietitian Nicolas Aubineau. The field tests we read confirm rare digestibility, with one trade-off: some testers find the taste a little less intense than the competition.
Authentic Nutrition is a French sports nutrition brand founded more than twenty years ago in the Chambéry area. Its recipes are developed by Emmanuelle Buisson, a dietitian and nutritionist. The brand says everything is made less than 150 kilometers from its offices and that it strictly complies with the European anti-doping standard. The range follows a simple three-step logic: before, during and after exercise. The Booster+ is the flagship of its during-exercise drinks.
The brand's promise rests on three pillars. First, a low-sugar formula that avoids blood sugar spikes. Second, zero additives, caffeine, taurine or plant extracts such as guarana. Third, an isotonic profile built to maximize intestinal absorption of carbs and sodium. On the brand's own website, the product is rated 4.86/5 across 534 customer reviews, a big number for a niche product like this.
| Brand | Authentic Nutrition |
| Model | Booster+ (isotonic energy drink) |
| Flavors | Lemon-lime, Red Berries, Peach |
| Formats | 40 g single-serve sachet, 500 g tub, 1500 g tub |
| Carbs | 34 g per 40 g serving (500 ml of prepared drink) |
| Ingredients | BCAAs, electrolytes (sodium, potassium, magnesium, zinc), vitamins B and C, minerals |
| Free from | Gluten, additives, caffeine, taurine, guarana, mate, ginseng |
| Made in | France (less than 150 km from the brand's offices) |
| Recognition | 1st place in the Nicolas Aubineau comparison (independent dietitian and nutritionist, 44 drinks tested) |
| Price | 3.99 euros for a 40 g sachet, 21.49 euros for a 500 g tub, 52.99 euros for a 1500 g tub |
© Authentic Nutrition, official photo used for editorial purposes
We looked at three independent French sources for this review. Each one used a different real-world testing approach, which lets us cross-check their findings.
RunActu (Yoann) tested the drink over several weeks, including at the Trail du Bout du Monde. He describes a taste that's "clearly there without giving you that unpleasant feeling of drinking grenadine or an ultra-sweet syrup," and found the lemon flavor especially refreshing. He confirms the drink's first place in Nicolas Aubineau's 2023 ranking of 44 energy drinks. He also advises against pairing the peach drink with the brand's peach gel, to avoid overloading your palate.
Run in Pyrénées tested product supplied directly by the brand, over several outings including one bike ride. The tester notes that "for an isotonic drink, the taste is there, but I'd call it fairly mild," which contrasts with RunActu's enthusiasm on the same point. On the essentials, though, the two sources agree completely: "no stomach issues," a drink that "makes you want to drink more than plain water" without any energy dip, and confirmation of the Nicolas Aubineau ranking.
Le Comparatif du Trail confirms that digestibility holds up over time, with no queasiness even after several hours of effort. It also points out that the brand earned three quality podiums from the same independent dietitian: energy drink, recovery drink and energy gel.
This split on taste intensity deserves to be flagged, not smoothed over. It shows the trade-off the brand openly makes: a low-sugar profile built to limit stomach trouble, and therefore a taste that will always be less pronounced than a classic isotonic drink.
© Authentic Nutrition, official photo used for editorial purposes
An isotonic drink has roughly the same concentration of carbs, water and salt as your blood. This property, called osmolarity, makes it easier for your gut to absorb nutrients and limits stomach discomfort during exercise. That matters most on long runs, when your stomach is already working hard from repeated fueling. By deliberately cutting the sugar content, Authentic Nutrition gives up some flavor intensity in favor of gut comfort. That choice explains both the unanimous praise for how well it's tolerated and the more measured reservations about taste.
RunMorph's advice: if your stomach struggles on long efforts, give the Booster+ a try in training before any race. If what you want above all is a very sweet, strongly flavored drink, this won't be your first pick.
| Criterion | Authentic Nutrition Booster+ | TA Energy Boisson Isotonique | SiS Beta Fuel Gel |
|---|---|---|---|
| Format | Drink powder, sachet or tub | Drink powder, tub | Ready-to-use gel |
| Carbs | 34 g / 40 g serving | 35 g / serving | 40 g / gel |
| Caffeine | None, ever | 0 to 40 mg depending on flavor | Depends on version |
| Positioning | Maximum digestibility | Value for money | Big carb dose |
| Price | 3.99 euros per 40 g sachet | 29.90 euros per 13-serving tub | About 2.50 euros per gel |
© Authentic Nutrition, official photo used for editorial purposes
© Authentic Nutrition, official photo used for editorial purposes
Yes, no question. This is exactly the problem the Booster+ formula sets out to solve, and all three sources confirm it works on that specific point.
Maybe not your first choice. The brand deliberately puts digestibility ahead of flavor intensity, so try it before buying a large tub.
No. The Booster+ contains no stimulants. Pair it with an occasional caffeinated gel late in the effort if you need one.
Authentic Nutrition's Booster+ delivers on its main promise: rare digestibility, independently confirmed by three French sources and by a benchmark ranking from a sports dietitian and nutritionist. The brand makes a clear trade-off, giving up a bit of flavor intensity to guarantee maximum gut comfort, and that explains the only real reservation in the reviews we read. Caffeine-free and priced slightly above some competitors, it targets a specific profile first and foremost: road and trail runners who have already had stomach trouble in races.
8.5/10: a French isotonic drink with rare digestibility, a step behind on flavor intensity, but backed by three independent field tests and a benchmark dietitian ranking.