Source Naturals Genistein Soy Complex is made from isoflavone-rich soybean powder that yields a consistent isoflavone content. This unique chemical-free process requires approximately 400 pounds of soybeans to yield just one pound of finished product. Genistein, an isoflavone phytonutrient derived from soybeans, has been the focus of scientific research since 1966. Studies have shown that genistein can bind to the same receptor sites as estrogen. Soybeans are the only significant dietary source of genistein; however, the amount of soy foods neccessary to meet the body's needs can be difficult to incorporate into today's diet. In Asia, where soy is a staple, the daily intake can be up to 20 times that of a Western diet.