According to the original book, the dosage of Duck’s Paw San is 6 grams of Ephedra, 6 grams of Radix et Rhizoma Glycyrrhizae, and 5 pieces of Fructus Bupleurum, which is recommended to be added or subtracted by the doctor in accordance with the specific situation. Duck’s Paw Essence is composed of ephedra, licorice and white fruits, in which ephedra can promote the lungs and calm asthma; white fruits can astringent the lungs and stabilize asthma, and used with ephedra, one astringent and one dispersing, and passes the lungs’ qi; licorice moderates the middle qi. Used together, the three herbs have the effects of astringing the lungs (converging lung qi) to stabilize wheezing, and at the same time resolving phlegm, etc., treating asthma, phlegm and salivary congestion (abnormal phlegm and excessive production of saliva), and so on. The adverse effects and contraindications of this formula are not known. To take this formula, it is usually necessary for the doctor to take into account the specific conditions of the disease to increase or decrease the dosage and the addition or subtraction of herbs, so it is recommended to use Duck’s Paw Essence under the guidance of a doctor, and never use it on your own.