Sun mushrooms (Agaricus blazei) are unique in that they are the only  medicinal mushroom without a history of use in Asia. It does however have a long history of use in Brazil and is used as a longevity tonic.

The active ingredient in A. blazei is a unique beta-glucan complex that activates the immune system by binding to T-lymphocytes and granulocytes, two cells responsible for fighting infections and repressing cancer growth.

A. blazei extracts contains the highest concentration of active beta-gulcans.

Hot-water extracts of Agaricus are availble in 400 mg capsules that contain 40% beta-glucans by weight.