Professor ZHANG Zhiyuan is experienced in treating diseases with the classical formulas

and has unique insights of the commonly used herb Gancao（Radix et Rhizoma Glycyrrhizae） about its preparation and effects. He advocates that the prepared Gancao in Treatise on Cold Damage and Miscellaneous Diseases（《伤寒杂病论》） is water-fried rather than the current honey-fried. Gancao can be used as an envoy medicinal to facilitate the function of the deputy medicinal

and can also be used to harmonize the actions of all medicinals in a formula and to reinforce healthy qi and dispel pathogen. As an important herb in the formula

Gancao is often used to clear heat and resolve toxins

nourish the heart and recover the pulse

and relieve fever with sweet-warm natures and flavors. It could be used for treating various diseases

however

the use should be appropriate.