We tend to put our hair through a lot, which is where the K18 Leave-In Molecular Repair Mask comes into play. This no-rinse hair treatment, made with a patented bioactive peptide, promises to reverse damage caused by colouring, heat and styling. Think of it as an apology note to your frazzled, stressed-out hair - one that works by repairing the keratin within each strand. You can expect stronger, softer and more manageable hair as that damage is repaired. If your hair is porous, crunchy, over-processed and generally past its best, you’ll want to know about this mask.