Thermogenesis is the process that increases the metabolic rate. Citrus aurantium delivers a unique combination of five adrenergic amines (synephrine, N-methyltyramine, hordenine, octopamin, and tyramine) to stimulate beta-3 receptors that increase the rate at which fat is released from the body stores (lipolysis) and increase the resting metabolic rate. At the same time garcinia extract, which includes (-) hydroxy citric acid (HCA), increases the production and storage of glycogen while reducing both appetite and weight gain. HCA also causes calories to be burned in an energy cycle similar to thermogenesis. White willow bark extract, standardized for salicin, provides a synergistic action in elevating energy expenditure. Studies have shown that salicin when used in combination with other thermogenic supplements helps promote increased fat oxidation. Green tea supplies natural caffeine and potent polyphenols (catechins), especially epigalloocatechin gallate (EGCG) that activates the central nervous system which elevates the body"s ability to burn calories and unwanted fat cells through the thermogenic process. Similar to green tea, Brazilian guarana, another source of natural caffeine, acts synergistically with other ingredients of Ultra Ripped to promote thermogenesis, Ultimate Nutrition"s Ultra Ripped (ephedra-free) capsules are manufactured under the strictest quality control to ensure your satisfaction. Ultra Ripped should be combined with physical activity, exercise and imrpoved diet.