Which herb appears in both Ban Xia Hou Po Tang and Zhu Ling Tang?

• A. Fu Ling
• B. Zhu Ling
• C. Ze Xie
• D. Hua Shi

Answer: (A)

The key idea is recognizing which herb shows up in both formulas and understanding what that herb does in each context. Fu Ling (Poria) is the shared ingredient. In Ban Xia Hou Po Tang, Fu Ling is included with Ban Xia and Hou Po to drain dampness and support the spleen in transforming phlegm that accompanies qi stagnation, helping to harmonize the middle burner and allow the rebellious qi to move. In Zhu Ling Tang, Fu Ling teams with Zhu Ling, Ze Xie, and Hua Shi to promote diuresis and clear damp-heat from the lower burner, while also balancing fluid metabolism. Because only Fu Ling is common to both formulas, it’s the herb that appears in both. The other herbs listed are not part of Ban Xia Hou Po Tang, so they don’t appear in both formulas.