味辛甘微涼．入足太陽厥陰經(jīng)．功專涼諸經(jīng)血．明目搜肝風(fēng)．得皂莢、蒺藜治皮痹不仁．得羌活、防風(fēng)治風(fēng)熱頭痛．血虛有火者慎用．惡石膏、烏頭．