Most mushrooms are very beneficial to humans and both cats and dogs, and less than 1% of mushrooms are harmful. The mushrooms that we use in Critical Immune Defense are “medicinal mushrooms” and they have been used to boost immune systems for centuries and are proven to be safe and effective for cats and dogs. For more than 30 years medicinal mushrooms have been approved as cancer treatments in Japan and China. More recently, the U.S. Food and Drug Administration (FDA) has approved clinical trials for Turkey Tail and other medicinal mushrooms. We didn't discover turkey tail," says lead investigator Leanna J. Standish, PhD, ND, LAc, FABNO, Medical Director of the Bastyr Integrative Oncology Research Center. "It's been used in Asia for thousands and thousands of years, and it turns out to be a really potent immune therapy. The significance, I think, is that we're bringing a new medicine to cancer patients in the U.S." Studies are being conducted at several U.S. research universities, including the University of Pennsylvania School of Veterinary Medicine to gather data on the cancer and tumor-fighting effects of mushrooms in dogs, and the development of transformative cancer therapy for pets. Please do your own online research to learn more about the benefits of the mushrooms in our product and the research being conducted. It is quite amazing!