The most specific Chinese formula for protection from external diseases is called Jade Screen (Yupingfeng San). The reference to jade means something that is valued and precious and in this case, because it protects. It consists of the following: Astragalus 10-15 grams, White Atractylodes 9-12 grams, Ledebouriella 9-12 grams. This formula has been known to preven and treat colds, flus and allergic rhinitis. Ledebouriella (also known as Saposhnikovia divaricata, or, in Chinese, Fang Feng, literally translated "guard against wind," meaning "external contagion" in this case). Ledebouriella is classified as acrid, sweet, slightly warm and more moist and balanced than other herbs that are used for treating external cold wind (meaning airborne and able to stimulate strong histaminic reactions). So it is a more balanced herb for these kinds of conditions. It's known as the most moist of the wind herbs. It can be used for all wind patterns, hot or cold. It treats both the upper and lower body as well as the exterior and interior. It's commonly used for headaches as well as diarrhea. It is effective for general body aches and spasms as well as relief of muscular tetany. It stops bleeding from the bowels which is one of the signs of severe flu strains. The combination of Ledebouriella with Astragalus, a well-known and powerful herb for the prevention of colds and flu is of great interest.