Dried and sliced thin, the root of the astragalus plant is a common component of Chinese herbal formulas. According to tradition, astragalus "strengthens the spleen, blood, and Qi; raises the yang Qi of the spleen and stomach; and stabilizes the exterior."1 Don't worry if you didn't understand what you just read, because without many months of training in traditional Chinese herbal medicine, there's no way you could have. Suffice it to say that the traditional understanding of the way astragalus works is different from the way it tends to be presented today.

In the United States, astragalus has been presented as an immune stimulant useful for treating colds and flus. Many people have come to believe that they should take astragalus, like echinacea, at the first sign of a cold.

The belief that astragalus can strengthen immunity has a partial basis in traditional Chinese medicine. The expression noted above, "stabilize the exterior," means helping to create a "defensive shield" against infection. However, according to tradition, astragalus formulas should not be taken during the early stage of infections. To do so is said to resemble "locking the chicken-coop with the fox inside," causing the infection to be "driven deeper." Rather, astragalus is supposedly appropriate only for use while you're healthy, for the purpose of preventing future illnesses.