Hair color is serious chemistry. Getting color into that hair shaft is no joke. That’s why Procter & Gamble employs 1,800 “beauty scientists” around the globe. I spoke to two of these beauty scientists this week who told me they have invented a kinder hair color, and that it marks the first significant advance in dye jobs in 50 years.
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Small, diffuse color molecules enter the hair, and while they’re inside, they oxidize and form a chemical reaction with a larger color molecule that’s already trapped in there. But the small molecules aren’t all that selective about who they get it on with, and they end up breaking some of the chemical bonds that hold hair together. That releases free radicals that make hair weaker and less able to resist things like aggressive brushing, blow-drying and ironing.
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So the beauty scientists came up with a whole new chemistry for getting the lightening molecules inside the hair. First, the new process works at a much lower pH. That makes it less alkaline, so it strips away much less of the lipid coating.