Ganoderma lucidum, commonly known as Reishi mushroom, has a long history of use in traditional Chinese medicine for promoting health and longevity. In recent decades, its use as an adjunct in cancer treatment has attracted scientific interest, particularly for its potential to reduce the side effects of conventional cancer therapies like chemotherapy and radiation.

Several clinical studies and meta-analyses suggest that Ganoderma may help improve quality of life and immune function in cancer patients. For example, a 2016 Cochrane review concluded that Ganoderma may enhance immune response (e.g., improve levels of CD3, CD4, and CD8 T-cells) and reported some evidence for improved quality of life, such as reduced fatigue and better appetite. However, the same review highlighted that the evidence is limited by small sample sizes, variability in study design, and a lack of rigorous blinding.

Although Ganoderma is not considered a standalone cancer treatment, there is modest scientific support for its use as a complementary therapy to reduce side effects and support immune function during cancer treatment. Most guidelines recommend its use only under medical supervision, as potential drug-herb interactions and adverse effects have also been reported. Thus, the evidence supporting Ganoderma’s use in cancer care is preliminary (rated 2/5), with further large-scale, high-quality studies needed to confirm its efficacy and safety.