Maitake mushroom (Grifola frondosa) has a long history of traditional use, but it is only recently that modern science has made possible the creation of a highly specialized maitake product, rich in beta-glucans. Dr. Nanba's Maitake Beta-Factor contains the only maitake beta-glucan fraction endorsed by the world's premier maitake researcher, Dr. Hiroake Nanba, Ph. D. This specialized beta-glucan fraction, MaitakeGold 404 , is a biological compound believed to have important health-promoting properties. Dr. Nanba's Maitake Beta-Factor combines MaitakeGold 404 with maitake fruiting body, maitake mycelia biomass, calcium, and vitamin C. This blend offers you a full spectrum of maitake activity.