Twinlab Ripped Fuel Extreme contains thermogenic fat fighting ingredients along with a proprietary herbal blend to promote weight lose. One of Ripped Fuel Extreme'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 maximum energy and power output. The Product: An advanced weight loss product that has Caffeine, Green Tea leaf extract, Cayenne fruit extract and L-Carnitine. End Result: Encourages the body to naturally promote fat metabolism. Science: Contains a thermogenic blend in addition to the herbal proprietary blend that works together to fight fat and promote lean body mass.