Smooth Response is a classic formula taken from The Discussion of the Spleen and Stomach by Li Dong-Yuan (Li Ao), 1249 A.D. His approach to health was based on the optimum functioning of the Earth phase of the Five Phases (wu xing). Run chang wan was designed to prevent injury to the Spleen resulting from Wind Heat attacking the Large Intestines and leading to internal dryness.

This formula is designed, with the actions of the notopterygium root in mind, to soothe the Liver and suppress Liver Wind, as well as counteract dryness. It is an excellent formula for constipation when a chronic Blood vacuity leads to the stirring of internal Wind (which may be accompanied by numbness and tremors in the limbs). Blood stasis resulting from Blood vacuity is addressed by the Blood-moving actions of the peach kernel and dong-quai tails.