Dr. Groot Hair & Scalp Dynamic Duo for color-treated hair and all scalp types. The 2-piece set includes Scalp Revitalizing Solution Hair Thickening Shampoo 385 mL / 13 fl oz and Miracle In Shower Treatment 250 mL / 8.4 fl oz. The formulas contain biotin and prebiotics and are made without parabens, silicones, or sulfates. Shampoo wet hair and scalp, rinse, then apply the treatment and rinse as directed.