Dui Yao, or paired herbs is an important concept of formulating herbs in Chinese medicine. Among 252 classical formulas written in Shang Han Lun during China’s Han Dynasty (206BC-220AD), 40 of them are formed with just two herbs, which is thought to be the earliest record of Dui Yao. Along the history of Chinese medicine, hundreds of Dui Yao have been developed and widely used by many different schools of herbal medicine theories. In each of the Dui Yao theories, the common thread is that the combination of the selected 2 herbs become more beneficial than it’s individual herb alone. Here are some of the most commonly recognized theories in formation of Dui Yao in Chinese medicine:
Enhancing each other: two herbs used together to enhance their effects in targeting a condition. For example, when Jin Jie (Schizonepeta Herb) is used together with Fang Feng (Saposhnikovia), their diaphoretics effect is enhanced.
Reducing each other’s toxicity: one herb is used to reduce the other’s potential toxicity. For example, when Ban Xia and Ginger are used together Ginger reduces the toxic aspect of Ban Xia, while strengthening the effect of stopping vomiting and nausea.
Pairing “warm” with “cold”: mixing two herbs with opposite properties like “warm” and “cold” to create synergetic effects. For example, Huang Lian and Wu Zhu Yu combination is Zuo Jin Wan (formula). Huang Lian is cold and Wu Zhu Yu warm, but the combination works out nicely for Liver fire and Stomach Qi imbalance.
Pairing “activating” with “calming”: blending two herbs with opposite properties of “activating” and “calming”. The pairing of Shu Di Huang (Cooked Rehmannia) and Rou Gui (Cinnamon Bark) represents “activating” Kidney Jing while calming Kidney Yang.
Pairing “loosening” with “tightening”: Gui Zhi’s (cinnamon) property is loosening up and Bai Shao is tightening up the Yang Qi. The combination of both forms the foundation for Gui Zhi Tang (Cinnamon Formula) for Cold/flu.
Blending multiple herbs to suit individual patient’s need is crucial in Chinese medicine. Mastering the understanding of Dui Yao theory improves practitioners’ results in helping their patients.