From the Manufacturer:
Astragalus [Immune, Circulatory] root has been used to promote immune function and as a tonic to build stamina. Ancient Chinese texts record the use of astragalus for tonifying the spleen, blood and chi.
Astragalus contains saponins, sterols, flavonoids, isoflavones and polysaccharides that have health-promoting benefits. Astragalus root may stimulate the immune system in many ways. It promotes the production of stem cells in bone marrow and lymph tissue and encourages their development into active immune cells. It appears to help trigger immune cells from a “resting” state into heightened activity. One study showed that astragalus root helps promote and maintain respiratory function. It also enhances the body’s production of immunoglobulin and stimulates macrophages. Astragalus can help activate T cells and natural killer cells. Several studies also show that astragalus demonstrates heart benefits, including protection against oxidative cellular damage. The flavonoids, saponins and polysaccharides found in astragalus root help minimize free radical damage on membranes.