Protect & 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 & 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 & Hair Treatment is the final step of a 3-part System, designed to strengthen the hair & amplify hair structure.