Astragalus Membranaceus Effects, Dosage, and Side Effects Beg Kei; Buck Qi; Huang Chi; Milk Vetch; Yellow Leader

... Astragalus is taken by mouth primarily because it is thought to improve immune function in a number of different ways. Multiple case reports and results from various studies of laboratory media, animals, and humans show that astragalus may improve the activity of existing immune cells and also may increase the production of new immune cells. Astragalus may also prompt the body to make other substances, such as interferon, which help to fight infections. In addition, some research shows that oral astragalus has mild antiviral activity. Therefore, it may help to prevent colds and other respiratory infections when it is taken consistently over long time periods. It is not very useful for treating colds or flu, however. Both the possible immune-boosting and antiviral effects of astragalus make its use widespread among people living with AIDS and other chronic conditions, including chronic fatigue syndrome. Although it appears to be safe when used in limited amounts, little scientific information supports its effectiveness as an antiviral agent. ...