Astragalus [Immune, Circulatory] root is being used to promote immune function and as stamna building tonic. Ancient Chinese texts indicate that astragalus has been used for tonifying the spleen, blood and chi. Astragalus contains saponins, sterols, flavonoids, isoflavones and polysaccharides which have health-protecting benefits. Through research astragalus root has been shown to stimulate the immune system in many ways. It increases the number of stem cells in bone marrow and lymph tissue and encourages their development into active immune cells. It appears to be helpful in triggering immune cells from a "resting" state into heightened activity. In one study astragalus root showed that it can help promote and maintain respiratory health. Astragalus 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 proffers heart-protecting effects, including protection against oxidative damage. The flavonoids, saponins and polysaccharides found in astragalus root help minimize free radical damage on membranes. Each capsule contains 420 mg of astragalus root. Take 2 capsules with a meal three times daily.