Turkey Tail is one of the most-studied beneficial mushrooms. It supports invigoration of immune cells while simultaneously making sure the immune response doesn’t overreact. As a prebiotic food for our probiotic microflora, it has also been shown to improve the gut microbiome.* Our supplements are made with organic mushroom mycelium grown on an organic brown rice substrate on our farm in the USA. We never use any fillers! Our mycelium and the fermented brown rice it’s grown on are immunologically active.* Host Defense was founded by renowned mycologist Paul Stamets. Backed by Paul’s 40 years of experience in mycology, we specialize in mushroom mycelium-based supplements to support natural immunity and whole body wellness. Scientifically validated to ensure quality and safety.