When you wash your hair, the shampoo opens the struttura surface of the hair – the cuticle. For this reason it is important to add una Care for your hair after washing to close the cuticle. This is exactly what conditioner will do. TRESemmé Rich Moisture. In addition to sealing hair fibers, it provides nourishment, hydration, and softening, essential for beautiful, shiny, and healthy hair. It protects hair from mechanical damage and dryness, and smoothes its surface, helping to soften it and making it easier to comb and perform subsequent treatments.