Design Essentials® STS EXPRESS Smoothing System Cleansing Sulfate-Free Shampoo - Step 1 is a gentle cleanser that removes impurities from the hair and scalp without stripping essential oils and nutrients from the hair. Infused with Biotin, this nourishing shampoo prepares the hair to absorb additional moisture and nutrients from Design Essentials® STS EXPRESS Smoothing and Strengthening treatment.