Nioxin System 6 Cleanser Shampoo - 1000ml. Part of Nioxin System No. 6 for chemically treated hair with progressed thinning. Nioxin’s cleanser shampoo System 6 for chemically treated hair with progressed thinning is the first step of a three part Nioxin regimen, specially formulated to strengthen the hair and amplify hair structure. Prepare the scalp and hair for a complete hair thickening treatment with Nioxin’s three part System 5 Cleanser for Coloured Hair with Light Thinning. Thanks to its Pro-Color Shield technology, this professional hair product helps remove sebum, fatty acids and other environmental residue from the scalp and hair. Available in 300ml and 1000ml bottles.