K18 Biometric Hair Science Molecular Repair Leave-in Hair Mask is a revolutionary hair mask that works at the molecular level to repair and restore damaged hair. This innovative treatment penetrates deep into the hair’s structure, repairing broken bonds and improving strength, elasticity, and smoothness. It is ideal for damage caused by coloring, heat styling, or chemical treatments. The result is healthier, shinier, and more manageable hair that feels restored from within. With a lightweight leave-in formula, it can be used after every wash for visible and long-lasting results and is free from sulfates, parabens, and gluten.