Reishi may be beneficial for supporting symptoms of conditions like diabetes, depression, and neurodegenerative diseases, but the current evidence is sparse. In clinical research, Reishi has been investigated as an adjunct to standard cancer treatments. Reishi may be beneficial for supporting symptoms of conditions like diabetes, depression, and neurodegenerative diseases, but the current evidence is sparse. In clinical research, Reishi has been investigated as an adjunct to standard cancer treatments.