Dietary Supplement Ultimate Immune Enhancer Modern science had identified in Maitake (Grifola frondosa) a Proteoglucan, protein-bound Beta-1,3 glucan and Beta-1,6 glucans (so-called D-fraction) as an active constituent to support the immune system. Maitake D-fraction is a standardized form of pure and active D-fraction specially developed to be optimal for oral administration. This product contains 4 times more D-fraction per tablet and provides 6 times more D-fraction per serving compared to Maitake D-fraction capsule.