This Hair Filler + Hyaluronic Acid Sulfate-Free Serum is formulated with hyaluronic acid, citric acid, and a repair care complex. This system fills curly and wavy hair with moisture for inner fiber repair, and outer visible transformation. Use this serum as step 4 in the 4-step system to rehydrate the hair. Inner fiber repair: Repairs & strengthens broken bonds deep in the cortex, hair fiber's inner layer*. Outer fiber repair: Locks in up to 15x more moisture**. Up to 100 hours of frizz control for defined curls with no weigh-down. Formulated without sulfates, silicones, parabens, phthalates, DMDM hydantoin, and mineral oil. All Garnier products, globally, are officially approved by Cruelty-Free International under the Leaping Bunny Program. *with continuous use of the system (Inner Fiber Repair Treatment and Moisture Repair Shampoo, Conditioner & Serum) **with the use of the system vs. non-conditioning shampoo