Nature's Way Astragalus is a powerful adaptogen known to provide immune support through its support of white blood cells, which are the cells of your immune system responsible for immune defenses.     Astragalus is an important herb in Chinese herbal practice for its ability to support vital energy and support the immune and glandular systems. It is considered to support body functions. It is harvested wild in Northern China and Mongolia. Early Chinese writings refer to astragalus as The Superior Tonic. It ranks as one of China's most important herbal tonics and is commonly used in Chinese cuisine.