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Why can hydrogen peroxide lighten hair color?

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How does an anole change its color? — coloration The anole changes color in response to its stress level.

Hydrogen peroxide ( $H_{2} O_{2}$ ) lightens hair color primarily through its function as an oxidizing agent. In the context of hair biology, the hair shaft is composed of a cortex containing pigmented material that determines the color of the mammalian coat.12

When applied to hair, hydrogen peroxide acts as a bleach by oxidizing the pigments within the hair shaft. This chemical reaction breaks down the pigment molecules, effectively removing or altering their ability to absorb light, which results in a lighter appearance of the hair. While hydrogen peroxide is widely used for such cosmetic purposes, it is important to note that solutions containing more than approximately 8 percent concentration are corrosive to the skin and must be handled with caution.1