WHAT IT IS BosDefense Nourishing Shampoo for Color-Treated Hair is a gentle sulfate free cleanser that removes toxins from the hair and scalp. WHAT IT DOES Bosley Pro BosDefense Nourishing Shampoo for Color-Treated Hair removes toxins such as D.H.T. from the hair and scalp skin a primary cause of hair thinning and hair loss. It helps to create a healthy environment for the hair and scalp while extending the life of color.