Syoss Repair Boost, 500 ml, Hair Masks for Women, The Syoss Repair Boost hair mask is an essential step in your hair care ritual. Give it a moment to regenerate and it will repay you with vitality and beauty. Characteristics: takes care of the lengths of weakened hair restores hair’s natural, healthy appearance restores hair structure How to use: Wash with shampoo, then apply to damp hair. Leave to act as instructed on the packaging, then rinse thoroughly.