Nioxin Scalp Therapy System #4 is designed for noticeably thinning, very fine color-treated hair. Hair is hydrated and fortified while maintaining a healthy shine. Scalp is refreshed and revitalized. Gently hydrate the hair without weighting it down. Amplifies hair density while refreshing the scalp. Nourishes the scalp with essential nutrients. Improves the appearance of thinning hair. Creates an environment for fuller, healthier looking hair.