CLA Pure 1000 from USN contains the highest concentration of two active CLA isomers (c 9, t 11 & tc 10, c 12). Both of these isomers have been identified as being helpful in the reduction of body fat & increase in lean muscle mass. USN CLA Pure 1000 is sourced from natural Safflower Oil & each batch of CLA Pure is laboratory tested to be free from impurities.