Reishi (Ganoderma lucidum) is a species of inedible fungi from the family Ganodermataceae. In many countries, Reishi fungi are considered as medicinal mushrooms, and the history of their use for medicinal purposes goes back to antiquity. It was believed that they promote longevity, strengthen the body's natural defense mechanisms and protect against many diseases. Traditional folk wisdom has been confirmed in scientific research.

Researchers identified specific compounds that determine the health-promoting potential of Reishi mushrooms. These include polysaccharides and triterpenes, among which the most important appear to be ganoderic, ganolucidic and lucidenic acids. The unique protein, GLPP (Ganoderma lucidum polysaccharide peptide), which is characterized by extremely strong antioxidant properties, is also of great importance.

Reishi fungi have an unprecedented ability to modulate the immune system. They alleviate the symptoms of asthma and allergies, promote remission of autoimmune diseases. In addition, they are a promising remedy against neurodegenerative diseases, cancer, diabetes, obesity and cardiovascular diseases. In experimental animal studies, it has been shown that they may extend lifespan by up to 20%.

Reishi fungi have a very high safety profile. Supplementation most often uses powdered extracts, standardized for the content of polysaccharides. For the convenience of users, they are enclosed in easy-to-swallow capsules. Those who find swallowing troublesome might want to choose liquid extracts instead.