Researchers tested 37 reishi mushroom products and kits sold in the United States and found that most were mislabeled. While products claimed to contain Ganoderma lucidum, over 93% of manufactured products actually contained Ganoderma lingzhi, a different Asian species. The study discovered that 86% of products tested contained something other than what the label claimed, which matters because different Ganoderma species have different chemical compositions and potentially different health benefits.