Coriolus versicolor, also known as Turkey Tail mushroom, has been the subject of significant scientific investigation, particularly in the context of immune support during convalescence, especially after cancer treatments. The mushroom contains active polysaccharopeptides, notably PSK (polysaccharide-K) and PSP (polysaccharopeptide), both of which have demonstrated immune-modulating properties in laboratory and clinical studies. In Japan and China, extracts of Coriolus versicolor have been used as adjuvant therapy for cancer patients to support immune function and recovery during and after conventional treatments such as chemotherapy and radiation. Several randomized controlled trials and meta-analyses suggest that PSK may enhance immune response, improve quality of life, and potentially increase survival rates in certain cancers, which are often periods of profound convalescence. However, most of these studies focus on cancer-related recovery, and evidence for general use in non-cancer convalescence (such as after infections or surgery) is more limited. Safety profiles are generally favorable, but further large-scale, high-quality research is needed outside of oncology settings. In summary, scientific evidence supports the use of Coriolus versicolor to aid immune recovery during convalescence, particularly in oncology, but with moderate strength and a need for broader studies.