Zanthoxylum nitidum 兩面針 Shiny-leaf Prickly Ash

The root of this shrub has been used as a painkiller for specific conditions in Chinese medicine since ancient times. It was described in the oldest classic Chinese medical literature, and is included in the Chinese pharmacopoeia. It has analgesic and anaesthetic effects, while its medicinal properties include “mild toxicity”, referring to its propensity to over-correct when restoring the disturbed Yin-Yang equilibrium in the body. It is thus usually prescribed in combination formulae so that its toxicity is neutralized by the other ingredients in the prescription during decoction. “Toxicity 毒 ” with respect to action mechanisms in Chinese medicine is different from “Poison 毒 ” in western medicine.