Improved Dissolving Formula. 0 Sugars. 10 Calories. Naturally Flavored. The advantage FRS Healthy Energy has over other energy products is simple. FRS is fueled by Quercetin, a powerful antioxidant that activated the body's energy-producing mechanisms-so you can stay at your best longer. Quercetin is found in foods like blueberries, apples and grapes. It works by naturally triggering the body's ability to product more real energy. The more energy your body creates, the longer you're able to push. And the longer you can push, the farther you'll go from a minor workout to a major marathon. One packet of FRS contains 35 mg of caffeine (equivalent to approx. 1/3 cups of coffee). Caffeine is used as metabolic enhancer to help the body absorb other key nutrients in the FRS formula.