Deeply hydrates for exceptional vibrancy and velvety-soft hair. This professional 5-step deep conditioning treatment is formulated with spring water algae extract to provide 5x the hydration of hyaluronic acid. Results last up to 5 weeks. No.1: Prepares the hair to ensure the absorption of No. 2 - No. 5.No.2: Deeply hydrates hair from the inside outNo.3: Olive squalane and moisturizing emollient oil repair the CMC structure to restore the hair?s ability to retain hydrationNo.4: Ethoxylated plant-based oil repairs and smoothes damaged cuticle layersNo.5: Meadowfoam seed oil seals in the treatmentNo.6 Weekly Booster : Olive squalane, moisturizing emollient oil, and meadowfoam seed oil refresh and prolong results. Use Indulging Hydration Weekly Booster at home to enjoy long-lasting results for up to 5 weeks.Use 1 vial per week for four weeks in place of regular conditioner to maintain salon results. After shampooing, massage into wet hair from mid-length to ends and leave on for 5 minutes, then rinse thoroughly.