This document discusses Ganoderma lucidum, commonly known as Reishi mushroom. It provides details on its traditional use in Chinese and Japanese medicine to treat diseases and promote longevity. The document outlines the biologically active compounds in G. lucidum such as polysaccharides, terpenoids, and proteins. Modern research has confirmed G. lucidum's immunomodulatory, anticancer, and other medicinal properties. Future research goals include clarifying taxonomy, identifying safe doses, optimizing cultivation conditions, and conducting clinical trials to provide evidence for G. lucidum-based medications.