San zi yang gin tang is a formula that acts mainly on the Lungs and Diaphragm and helps to reduce the stagnation of mucus in the body. It also regulates the circulation and descent of Qi. San zi yang gin tang warms the Lungs and relaxes the Diaphragm, thus reducing excess mucus that obstructs them. This action is encouraged by the downward stimulation of the Qi. It helps to eliminate mucus caused by food stagnation. Thus, San zi yang gin tang warms the lungs, regulates lung Qi and solves mucus problems.