Protect and refresh the scalp with Nioxin\'s 3-part System 4 Scalp & Hair Treatment for Coloured Hair with Progressed Thinning. This diameter-increasing leave-in hair and scalp treatment is particularly formulated for coloured hair with progressed thinning. Nioxin\'s treatment Scalp Access 2.0 technology helps prevent hair loss due to breakage, providing a refreshed scalp environment. Nioxin\'s Scalp and Hair Treatment is the final step of a 3-part System, designed to strengthen the hair and amplify hair structure.