The longer the interval between dyeing hair, the better. Generally, the interval should be at least 3 months. It is not recommended to dye your hair more than 4 times a year, but it is better to dye it 1-2 times a year.

Excessive hair dyeing will aggravate the influence of hair dye on health. The main reason why hair dye colors hair is that it contains chemicals, one of which is called p-phenylenediamine, which is harmful to human body.

If you dye your hair frequently, phenylenediamine will promote benzene organic compounds to enter the blood circulation through the scalp by heating during the dyeing process, and then reach the bone marrow with the blood. Long-term and repeated effects, from quantitative change to qualitative change, will lead to pathological changes of hematopoietic stem cells and even lead to tumors in the blood system. It is well known that leukemia may be related to long-term use of inferior hair dyes.

In addition, many people will have an allergic reaction to the chemical composition of hair dye.

When dyeing your hair, you should choose a qualified brand when choosing a hair dye. Don't blindly listen to advertisements and go to a regular barber shop to avoid dyeing your hair many times in a short time, so as not to cause irreversible harm to your body.