PSP And PSK (Beta Glucans)

There are two extracts derived from the Coriolus mushroom that provide immune boosting properties as well as the anti-cancer properties that you will discover through our database of published medical studies. These extracts are called PSK, Polysaccharide-K and PSP or Polysaccharide Peptide and are form of Beta Glucans


PSK is an isolated component of the Coriolus versicolor mushroom and not an isolated compound and therefore can only be summarized by close approximation. It main polysaccharide chain consists of beta gluten with side chains where the protein of PSK is attached.

Protein-bound polysaccharides, designated as PSK and PSP, have been isolated from the CM-101 strain and the COV-1 strain, respectively, of the mushroom Coriolus versicolor.

PSP possesses a molecular weight of approximately 100 kDa. Glutamic and aspartic acids are abundant in its polypeptide component, whereas its polysaccharide component is made up of monosaccharides with alpha-1,4 and beta-1,3 glucosidic linkages. The presence of fucose in PSK and rhamnose and arabinose in PSP distinguishes the two protein-bound polysaccharides, which are otherwise chemically similar.

PSP is classified as a biological response modifier. It induces, in experimental animals, increased gamma-interferon production, interleukin-2 production, and T-cell proliferation. It also counteracts the depressive effect of cyclophosphamide on white blood cell count, interleukin-2 production and delayed-type hypersensitivity reaction. Its antiproliferative activity against tumor cell lines and in vivo antitumor activity have been demonstrated. A small peptide with a molecular weight of 16-18 kDa originating from PSP has been produced with antiproliferative and antitumor activities.

PSP administered to patients with esophageal cancer, gastric cancer and lung cancer, and who are undergoing radiotherapy or chemotherapy, helps alleviate symptoms and prevents the decline in immune status.

PSK  & PSP Extraction

Historically, Coriolus was picked, dried and steeped in boiling water and drunk as a tea to gain access to its properties. Today, PSK is extracted using a  hot water/ethanol process using the fruit bodies of the mushroom. This provides a capsulated form of the PSK component of the mushroom which can be taken orally.

Real PSP is Never Produced From Fruit Bodies

Published scientific studies of PSP have used only extracts derived from the mycelia stage of the mushroom lifecycle, not extracts from fruitbodies (mature mushrooms). The PSP extracted from mycelia is chemically different to extracts from the fruit body later in the mushroom lifecycle. There are differences in monosaccharide composition (PSP has Galactose) and protein composition (PSP has peptides).
It is the chemical composition of PSP from mycelia that has been the subject of scientific research.

The only known process capable of producing the pure and potent Coriolus Versicolor mycelium needed as the raw material for research-quality PSP is to extract from mycelia produced through deep layer cultivation in pharmaceutical grade sterile production facilities. (Real PSP is never produced from fruit bodies extract taken from

Recently a mycelium stem extraction has produced a higher potency of both PSK and PSP extractions. This has been difficult to obtain in the US but is now available.

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