Nioxin System 1 Cleanser Shampoo for natural hair with slight thinning is the first step in a three-part Nioxin routine, specially formulated to strengthen hair and hair structure. This professional shampoo cleans the skin and removes dirt, excess oil and other environmental residues from the scalp and hair. This clinically and dermatologically tested shampoo contains niacinamide and biotin that hydrates the scalp and hair from root to tip while thickening and strengthening the hair structure. Finish with Nioxin System 1 Conditioner and Nioxin System 1 Treatment for best results. Available in 2 sizes: 300 ml and 1000 ml.