Prescribed for damaged hair, Redken Extreme Shampoo cleanses, strengthens, and restores damaged hair while helping prevent future hair breakage. Formulated with Redken's Strength Complex containing Amino Acids and Arginine, hair is strengthened and fortified while Citric Acid balances hair's pH to condition and add smoothness. Pros recommend managing and treating dry, damaged hair with the complete Extreme hair care system.