Nioxin’s cleanser shampoo system 4 for coloured hair with progressed thinning is the first step of a three part Nioxin regimen, specially formulated to strengthen the hair and amplify hair structure. It prepares hair and scalp for a complete hair thickening treatment with Nioxin’s three part System 3. This professional derma-purifying Cleanser Shampoo removes dirt, excessive oil and other environmental residues from the scalp and hair.