Under normal circumstances, moxa leaves wash hair usually does not produce side effects, but if allergic to moxa leaves, may make the appearance of allergic reactions. Mugwort leaves are pungent, bitter and warm in nature; they are slightly toxic. It belongs to the liver, spleen and kidney meridians. It can warm menstruation and stop bleeding, dispel cold and relieve pain; it can be used externally to dispel dampness and relieve itching. It is used for spitting blood, epistaxis (all non-trauma-induced external bleeding in certain parts of the body), metrorrhagia (excessive menstrual flow or more than a few drops), fetal leakage (small amount of vaginal bleeding in early pregnancy), hyperemesis, cold pain in the abdomen, menstrual cold, cold uterine infertility, etc. It is used externally to treat itching of the skin. However, if an allergic reaction occurs after washing hair with mugwort, such as itchy scalp, dandruff, etc., you should stop using it immediately and seek medical attention.