Astragalus is a Chinese herb that has traditionally been used to promote immune function and build stamina. It ranks as one of China's most important herbal medicines. It is harvested wild in Northern China and Mongolia. Early Chinese writings refer to Astragalus as "The Superior Tonic".
Astragalus is used to boost the immune system and defend against viruses that are associated with the common cold. It increases the activity of while blood cells and this in turn, increases the production of antibodies to neautralize bacteria and viruses. Astragalus also enhances the production of interferons, which defent against viral infections. Moreover, Astragalus stimulates natural killer cells whose job is to keep the infection from spreading.