“When the Shang Han Lun Speaks: Understanding the System Behind the Formulas”
During the course of my studies, the clarity and systematic use of herbal formulas in the Shang Han Za Bing Lun continues to amaze me. At times, it feels as though Zhang Zhongjing is speaking directly to us across time.
Let me illustrate this with an example.
Dang gui (當歸, Angelicae sinensis radix) can be understood as a representative herb for treating Jue Yin Liver Blood deficiency. This characteristic explains its use in Blood-nourishing formulas such as Dang Gui San and Dang Gui Shao Yao San.
Dang gui san
dang gui 12 bai shao 12 chuan xiong 12 huang qin 12 bai zhu 6
Dang gui shao yao san
dang gui 9 bai shao 48 chuan xiong 24 bai zhu 12 fu ling 12 ze xie 24
In both of these formulas, dang gui is combined with bai shao and chuan xiong. The inclusion of chuan xiong ensures that the newly generated Blood continues to move. Without this movement, the Yin-nourishing aspect could overwhelm the already weakened Yang. This pairing teaches us an essential principle: the dynamic balance between Yang transformation and Yin nourishment. When one aspect is deficient, the other is inevitably affected.
In Dang Gui Jian Zhong Tang, we see this same strategy applied in a different context. Again, dang gui and bai shao are paired, but here it is gui zhi that supports and protects the Yang from being overpowered. The combination of gui zhi and sheng jiang works together to balance the nourishing qualities of dang gui and bai shao.
Dang gui jian zhong tang
dang gui 9 gui zhi 9 bai shao 18 sheng jiang 9 da zao 9 zhi gan cao 6 yi tang 30ml
This formula is based on Gui Zhi Tang, where gui zhi and bai shao are already used in a carefully balanced relationship. In this context, sheng jiang plays a key role: it helps release the exterior and supports the upward movement of clear Qi toward the upper burner, where the Heart and Lungs distribute it throughout the body.
Gui zhi tang
gui zhi 9 bai shao 9 sheng jiang 9 da zao 9 zhi gan cao 6
We see sheng jiang used in a similar way in Dang Gui Si Ni Jia Wu Zhu Yu Sheng Jiang Tang, where it reinforces the warming and circulating functions of the formula.
Dang gui si ni jia wu zhu yu sheng jiang tang
dang gui 9 gui zhi 9 bai shao 9 sheng jiang 24 da zao 15 zhi gan cao 6 xi xin 9 tong cao 6 wu zhu yu 18
In Dang Gui Si Ni Tang, however, sheng jiang is omitted and the emphasis shifts slightly, with xi xin taking on a more prominent role in warming the channels. Despite this modification, the underlying system remains consistent.
Dang gui si ni tang
dang gui 9 gui zhi 9 bai shao 9 da zao 15 zhi gan cao 6 xi xin 9 tong cao 6
If we only memorise formulas, we inherit their surface. But if we study their structure, we inherit their intelligence. Each combination of herbs reflects a deliberate strategy, one that balances movement and nourishment, Yin and Yang, root and branch. When we learn to see this, the formulas are no longer fixed prescriptions, but living teachings. In this sense, it is as if Zhang Zhongjing is still guiding us, showing us how to think through the medicine itself.
