In the 1970s, scientists started to search for mutagens from food in hopes of eventually using this knowledge to help prevent cancer. Based on reports that overcooked meat contained mutagens, Dr. Pariza at the University of Wisconsin-Madison investigated the correlation between mutagen formation and cooking temperature and time using ground beef. To their surprise, in addition to mutagens in beef extract they also found a compound that had anti-mutagenic activity (Pariza and Hargraves 1985). This compound was identified and named conjugated linoleic acid (CLA) – the main ingredient of Clarinol XS. In addition to its originally identified anticancer activity, Clarinol has shown a wide range of biologically beneficial activities; decreased severity of atherosclerosis, reduction of adverse effects of immune stimulation, and, most interestingly, a reduction of body fat and an increase in lean body mass in several animal species (Pariza 2004; Park and Pariza 2007). Clarinol XS represents a unique source of the bioactive form of CLA and L-carnitine which helps to degrade body fat, at the same time, has a positive influence against repeated fat deposition (the yo-yo effect).