The Nioxin System 4 treatment clears the hair of follicle blocking sebum, fatty acids and residues. In addition, it hydrates the hair whilst improving hair fullness, resilience and protecting hair colour. Suitable for coloured hair with progressed thinning. Step 2 in the full System 4 treatment, the Color Safe Scalp Therapy Revitalizing Conditioner nourishes the hair and optimises it for further treatment. To use: Apply to the scalp and work to the ends. Leave for 1 to 3 minutes before rinsing.