A: Both feature reparative properties, but they serve very different purposes. Moisture Repair Shampoo and Conditioner infuse damaged, weakened hair with proteins and reconstructive keratin to strengthen the hair shaft. Smoothing Shampoo and Conditioner contain AminoRenew™ which restores amino acids back into frizzy, unruly hair. This infusion mends broken disulfide bonds, which helps to align the hair shaft— resulting in more manageable hair with a smooth appearance. Additionally, the two collections address different primary need states: products to repair damaged hair vs. products to tame and control frizzy hair.