Conformation changes in human hair keratin observed using confocal Raman spectroscopy after active ingredient application.

From these experiments, we concluded that the effective active has a smoothing effect on the human hair fibres by acting on α-helix and β-sheet keratin conformation and on the tertiary structure of keratin. Based on these results, confocal Raman spectroscopy can be considered a powerful technique for investigating the influence of hair cosmetic ingredients on keratin structure in human hair fibres. Moreover, this analytical technique has the advantage of being non-destructive and label free; in addition, it does not require sample extraction or purification and it can be applied routinely in cosmetic laboratories.