It is best to wash your hair once every 2-3 days, not every day, and it is best to wash it between 7-10 pm. The normal scalp has its own metabolic law, about 2-3 days the cells of the surface layer of the scalp due to metabolism and in the shedding stage, this time will produce more obvious dandruff, individual people will appear mild itching symptoms. This time is ideal for washing hair with warm water, which can effectively clean the dandruff that is about to fall off or has fallen off as well as the secreted oil. From 10:00 pm to 2:00 am, the period of regeneration and active scalp cells, washing your hair within 3 hours before this is good for hair growth and can also protect the skin of your head. The water temperature should not be too high when washing your hair to avoid scalding the skin and triggering irritating hair loss. Do not wash your hair immediately after sweating to avoid sudden temperature changes in the scalp area, which may cause discomfort.