Huh? What "other stuff"? EE-EPA is much cheaper to make than rTG-EPA, the other form available as a DS - but the natural form of EPA, meaning it doesn't go through a chemical conversion process, oxidizes very easily and you can't concentrate it above the ratio of EPA/DHA found in fish, of which EPA is about 30% of total O3 content - that's standard "fish oil" and it's of nearly no value for therapeutic or medical uses.