The damaging effects of oxidative bleaching are most evident in hair which has been lightened from dark shades to platinum blonde. Whilst conventional conditioning agents effectively manage cuticular damage, the reversal of cortical weakening of hair poses a greater challenge. A number of protein-derived commercial actives claim the ability to strengthen the hair fibre when used in conditioning products. The aim of this study was to compare the relative efficacy of hydrolysed wheat protein, L-arginine and hydrolysed collagen in improving wet and dry tensile properties of heavily bleached hair tresses
