Maitake (Grifola frondosa) has been prized in traditional Japanese herbology for hundreds of years.Modern science has identified in Maitake Proteoglucan, Beta-1,3 glucan and Beta-1,6 glucans combined with protein, as an active constituent to support the immune system.*Maitake D-fraction is standardized form of pure and active Proteoglucan, specially developed to be optimal for oral administration.Every 20 drops contains a minimum of 5.5 mg of D-fraction (a Beta-glucan protein complex), extracted from organically grown Maitake fruit body in vegetable glycerine base.