A Study of the Photolightening Mechanism of Blond Hair with Visible and Ultraviolet Light

September 2004 in “ International Journal of Cosmetic Science ”

Toshihiro Takahashi, Kōichi Nakamura

visible light ultraviolet light blond hair melanin granules hair tissues VIS light UV light

TLDR Blond hair lightens more with visible light directly, while ultraviolet light lightens it after washing by damaging other hair parts.

The study investigated the photolightening behavior of blond hair under visible (VIS) and ultraviolet (UV) light. It was found that VIS light contributed more significantly to the lightening of blond hair than UV light, acting directly on the hair, while UV light required the hair to be washed post-irradiation to show lightening effects. Both VIS and UV light lightened isolated melanin granules similarly, indicating that melanin granules are equally sensitive to both types of light. However, UV light damaged hair tissues excluding melanin granules, whereas VIS light did not. The study concluded that UV light damages hair tissues, leading to lightening after washing, while VIS light directly decomposes melanin granules, lightening the hair without the need for washing.

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Research cited in this study

1 / 1 results

research Photochemical Alterations in Human Hair: Artificial Irradiation and Investigations of Hair Proteins

27 citations, January 1995

Melanin in black hair protects it from sun damage better than light-brown hair.

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research A Study of the Photolightening Mechanism of Blond Hair with Visible and Ultraviolet Light

7 citations, September 2004 in “International Journal of Cosmetic Science”

Blond hair lightens more with visible light directly, while ultraviolet light lightens it after washing by damaging other hair parts.