Propel is sweetened with two zero-calorie artificial sweeteners: sucralose and acesulfame potassium (often listed as Ace-K on labels). This applies to both the bottled water and the powder packet versions. The drink contains zero calories and zero grams of sugar.
Why Propel Uses Two Sweeteners Instead of One
Sucralose and acesulfame potassium are combined in Propel for a specific reason: together, they mimic the taste of real sugar more closely than either one alone. Sucralose delivers the bulk of the sweet flavor, but it lingers in the mouth longer than sugar does. Acesulfame potassium hits quickly but fades fast and can leave a slightly bitter edge on its own. Blending them creates a sweetness curve that rises and falls more like regular sugar, which is why this particular pairing shows up in a wide range of zero-calorie drinks and foods.
Sucralose is about 600 times sweeter than sugar, and acesulfame potassium is roughly 200 times sweeter. Because so little of each is needed, Propel stays at zero calories and zero carbohydrates per serving.
How Propel Compares to Similar Drinks
Propel and Gatorade Zero are both made by PepsiCo and marketed as low-calorie electrolyte drinks, but they’re not identical. Gatorade Zero contains 5 calories and 1 gram of carbohydrates per 20-ounce bottle, while Propel has zero of both. Both use sucralose and acesulfame potassium as their sweetening base. Propel is positioned more as an everyday flavored water, while Gatorade Zero leans into heavier sports recovery. If your main concern is the type of sweetener, though, the two products are essentially the same on that front.
What These Sweeteners Do in Your Body
Neither sucralose nor acesulfame potassium contributes calories or raises blood sugar the way regular sugar does. Your body doesn’t break them down for energy. That’s the basic appeal for anyone watching calorie or sugar intake.
However, some research suggests the picture may be more nuanced than “zero effect.” A randomized, double-blind trial published in the journal Diabetes Care had healthy adults consume 200 milligrams of sucralose daily for four weeks. Compared to placebo, the sucralose group showed reduced insulin sensitivity and a lower initial insulin response to sugar. The researchers noted these were statistically significant changes, though they cautioned that longer studies are needed to determine whether these shifts matter clinically over time. For context, 200 milligrams of sucralose is considerably more than you’d get from a single bottle of Propel, but the findings are worth knowing if you drink multiple artificially sweetened products throughout the day.
Acesulfame potassium has been less studied on its own, but the FDA has set an acceptable daily intake of 15 milligrams per kilogram of body weight. For a 150-pound person, that works out to about 1,020 milligrams per day, a threshold that would be very difficult to reach through normal consumption of flavored waters.
What’s Not in Propel
Propel does not contain aspartame, stevia, or sugar alcohols like erythritol. If you’re specifically trying to avoid aspartame (the sweetener in older diet sodas), Propel is free of it. It also contains no high-fructose corn syrup or regular sugar. The ingredient list is relatively short: water, citric acid, the two sweeteners, electrolytes (sodium and potassium), and added B vitamins.
If you prefer drinks sweetened with stevia or monk fruit instead of synthetic sweeteners, Propel isn’t the product for you. Several competing electrolyte brands use those plant-derived alternatives, though the taste profile is noticeably different.