PureologyStrength Cure Strengthening Shampoo for Damaged Color-Treated HairPureology Strength Cure Shampoo fortifies and repairs damaged, colour treated hair with key ingredients Keravis and Astaxanthin and a signature aromatherapy blend of Raspberry, Peach and Water Flowers. HOW IT WORKS Apply a dime sized amount of Strength Cure Sulfate Free Shampoo to wet hair at the scalp. Lather and work down to the ends. Rinse. For extra cleansing, repeat the same procedure. Follow with Strength Cure Conditioner for best results.