Optimum Nutrition (ON) Amino Energy is a pre-workout supplement designed to provide energy and support muscle recovery. It contains a blend of amino acids, green tea, and green coffee extracts, making it keto-friendly and free from sugar. Each serving delivers 100 mg of caffeine from natural sources to help you stay energized and focused throughout the day or during workouts. The watermelon-flavored powder is easy to mix and can be consumed anytime for an energy boost.