The special feature of quasi-drug hair coloring products is that once they are used to color hair their dyeing power lasts for up to several months. Furthermore, they can lighten black hair and they have a wide range of uses from hair dyeing to changing the color of hair to a brighter one. Although we use one phrase to describe hair coloring products, in fact there are many varieties. I will introduce you to these below.

Oxidation hair dyes

Currently, oxidation hair dyes are the most widely used and common hair coloring products. Using an oxidation dye once, the color will hold for around 2-3 months so they are also called 'long-lasting hair dyes'. Recently, there are also types which promise reduced odor and low stimulation. In hair coloring products these are good for most hair dye colors, so oxidation hair dyes have a dominant share of the hair coloring market.

Bright coloring

Hydrogen peroxide, which contains agent 2, bleaches the melanin pigment in hair and brightens the color of black hair. The special features of this oxidation agent are that it can add bright chestnut-color streaks to hair and also turn pitch black hair brown.
When the volume of the alkali, containing agent 1, and hydrogen peroxide, containing agent 2, are adjusted, it is possible to change the brightness of hair color.

Rash problem

Oxidation that includes agent 1 (diamine-based dyes etc.) sometimes cause rashes, depending on the user's constitution and physical condition. Therefore, each time before use it is necessary to perform a patch test. People that get rashes from oxidation dyes cannot use them.

Requirement of an approval application for sales and marketing

In order to manufacture and sell oxidation hair dyes it is necessary to make an application for approval for each product to the prefectural governor.

Form of product

Cream and liquid types are most common, but there are also products which use aerosol, foam and fine powder types.

Usage rules

When using quasi-drugs, after mixing agent 1 (active ingredient: oxidation dye) and agent 2 (active ingredient: hydrogen peroxide), generally it should be applied to the hair. After applying they should be left for a short while and the oxidation dye color will establish inside the hair. After washing away, the hair will be colored to your choice.

Other Quasi-Drug Hair Color (Bleach lotion)

Bleach is used to remove coloring from hair that has been decolorized or that has had a hair coloring applied one time. It is common to apply to hair and use bleach after mixing together agent 2 with agent 1 in cream or powder form. Hydrogen peroxide, which includes agent 2, breaks down and decolorizes the color which has been established inside the hair through coloring and melanin pigments in the hair and then brightens the hair color. This approach does not include an oxidation dye, so mostly there are no fears of rashes occurring. However, if not enough care of the hair is taken then there is a danger the hair might be damaged, so it is important to be careful. Furthermore, in the case of a hair color that has been darkened by a hair coloring product or similar, it is very difficult to completely decolorize the hair.

Color removing formula

This type blackens the hair color in response to polyhydric phenol and iron ions inside the hair. This does not contain oxidation dye, so it can even be used on hair that easily gets a rash from oxidation dyes. Recently this type has not been commercialized so often. This is for several reasons, such as it can only color hair black, it cannot brighten black hair and it has poor compatibility with perms (it is difficult to perm hair which has been colored black in this way).