Xanthium 12 is based on modern Chinese research into individual herbs and complex formulas for treating allergies. These herbs have been shown to inhibit at least one part of the cascade of events that leads to the common allergy symptoms. For example, many of them inhibit excessive secretion of histamine. Unlike antihistamine drugs, these herbs do not cause drowsiness. This particular formula was based primarily on treatments that were tried clinically for allergic rhinitis, which rely on xanthium, siler, mume, and licorice. The formula has been used in the U.S. for 15 years and is not reported to cause adverse reactions. Xanthium 12 includes herbs that clear heat (sophora, bupleurum, scute, moutan); herbs that tonify and astringe (ginseng, licorice, mume, schizandra); and herbs that dispel wind (xanthium, centipeda, cynanchum, and siler).