Twinlab Ultimate Diet Fuel contains thermogenic fat fighting ingredients along with CycloBurn proprietary herbal blend to promote weight lose.* One of Ultimate Diet Fuel\'s thermogenic ingredients is Caffeine. Caffeine is a power and energy accelerant!* It\'s perfect to super energize your body for powerful workouts.* This fast-acting substance delivers the right molecular structure to your energy systems for optimal energy and power output.* Caffeine acts to increase mental alertness and neurologically provide the surge you need to support your training.* Not just a stimulant, this powerful substance reaches deep into the muscle cell to provide lasting power and delaying the onset of muscle fatigue.*