1, clearing away heat and toxic materials: Folium Isatidis has the function of clearing away heat and toxic materials, and is often used to treat heat toxin, erysipelas, sore throat, sores on mouth and tongue, sores, carbuncle and other diseases. When using Folium Isatidis, it should be noted that it can not be combined with other drugs for clearing heat and purging fire, which may easily lead to the aggravation of the symptoms of spleen and stomach deficiency and cold.

2. Cooling blood and stopping bleeding: Folium Isatidis has the effect of cooling blood and stopping bleeding, and can be used to treat hematemesis and epistaxis. "Materia Medica Zhengzheng": Treat plague, fever, rash, carbuncle, swelling and pain, remove polydipsia, stop epistaxis and hematemesis, and kill carbuncle and scabies. Anyone who suffers from heat and poison should use it by pounding the juice with blue leaves.