On the surface, the formula Xiang Sha Yang Wei Wan (Costusroot and Amomum Stomach-Nourishing Pill) appears similar to other spleen-fortifying, damp-drying formulas such as Xiang Sha Liu Jun Zi Tang (Costusroot and Amomum Six Gentlemen Decoction). Both formulas contain the spleen-fortifying base of Si Jun Zi Tang (Four Gentlemen Decoction) with damp-drying medicinals from Er Chen Tang (Two Matured Ingredients Decoction), plus the Mu Xiang and Sha Ren that the formula is named after. However, despite their similarities there are significant differences between these two formulas.

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Most of us learn Xiang Sha Liu Jun Zi Tang as a natural progression of Si Jun Zi Tang. Si Jun Zi Tang contains Ren Shen, Fu Ling, Zhi Gan Cao, and Bai Zhu, which gives it an essentially pure principle of spleen supplementation. Because spleen vacuity often co-exists with dampness, it is common to add Chen Pi and Ban Xia to dry dampness and promote the spleen’s ability to move and transform (this makes Liu Jun Zi Tang). Cases with added signs of dampness (particularly middle burner symptoms) are treated by adding the warm, drying, aromatic and qi-moving agents Mu Xiang and Sha Ren. This makes Xiang Sha Liu Jun Zi Tang.

The progression from Si Jun Zi Tang to Liu Jun Zi Tang and Xiang Sha Liu Jun Zi Tang illustrates the basic spectrum of spleen-supplementing and damp-drying approaches, and we tend to use each of these formulas dynamically depending on the patient’s individual presentation. Less dampness keeps us closer to Si Jun Zi Tang theory while more dampness moves us in the direction of Xiang Sha Liu Jun Zi Tang. Liu Jun Zi Tang offers a balance of spleen-supplementing and damp-drying; it is weaker for dampness than Xiang Sha Liu Jun Zi Tang but it is less warming and drying.

In some ways, Xiang Sha Yang Wei Wan could be considered to be a formula that is one step further down this continuum, with a relatively strong damp-drying, warm aromatic nature. It contains all the ingredients of Xiang Sha Liu Jun Zi Tang except for the Ban Xia, and it additionally brings in Cang Zhu, Hou Po, Xiang Fu, Bai Dou Kou, Da Zao, and Gan Jiang. These additions further increase the qi-moving, damp-drying, and warm aromatic effect. While inappropriate for heat patterns, the added warmth provided by medicinals such as Bai Dou Kou and Gan Jiang allows for better control of cold-damp conditions. As with Xiang Sha Liu Jun Zi Tang, the focus in Xiang Sha Yang Wei Wan remains clearly on the middle burner (in fact, the principle of drying dampness often applies to the middle burner specifically).

In Xiang Sha Yang Wei Wan, we can see the base formula Li Zhong Wan in addition to Si Jun Zi Tang, which implies that the formula is more targeted to cold patterns of the middle burner. Using Cang Zhu and Bai Zhu together gives a more powerful damp-drying effect than Bai Zhu alone would provide, and the combination of Cang Zhu, Hou Po, and Chen Pi within Xiang Sha Yang Wei Wan incorporates the principle of Ping Wei San (Stomach-Calming Powder). Additionally, the presence of Xiang Fu gives Xiang Sha Yang Wei Wan another qi-moving angle by bringing in a liver qi-coursing influence. Taken as a whole, we can see numerous base formulas within Xiang Sha Yang Wei Wan, including: Ping Wei San, Xiang Sha Liu Jun Zi Tang, Li Zhong Wan, Si Jun Zi Tang, and Liu Jun Zi Tang.

The base formulas within Xiang Sha Yang Wei Wan are each eloquent, concise and time-tested formulas on their own. While Xiang Sha Yang Wei Wan encapsulates a complex blend of multiple formulas, it remains elegant and straightforward, with a single clear, unified direction. Try it for a combination of cold-damp obstruction of the middle burner and spleen vacuity.