The Science Behind Hair Dye
Some permanent hair dyes contain the two main ingredients of hydrogen peroxide and ammonia. The ammonia causes the outer layer of the hair to swell, which enables the other chemicals in the dye to sink into the core of the hair where the melanin (the part of the hair that gives it the color) is stored. The hydrogen peroxide acts as the oxidizing agent as it bleaches the hair, and makes the dyeing molecules form into larger molecules that can’t escape the core. This makes the color permanent.
Some permanent hair dyes contain the two main ingredients of hydrogen peroxide and ammonia. The ammonia causes the outer layer of the hair to swell, which enables the other chemicals in the dye to sink into the core of the hair where the melanin (the part of the hair that gives it the color) is stored. The hydrogen peroxide acts as the oxidizing agent as it bleaches the hair, and makes the dyeing molecules form into larger molecules that can’t escape the core. This makes the color permanent.