K18 Biomimetic Hairscience line: the AstroLift™ Reparative Volume Spray and the Leave-In Molecular Repair Hair Mask. These products are designed to work together, with the mask repairing internal hair structure and the spray providing external volume and further repair. How to Use Them Together For maximum results, follow this routine: Shampoo: Wash hair but skip conditioner, as it can block the K18 peptide from penetrating the hair shaft. Apply Mask: Towel-dry hair and apply the Leave-In Molecular Repair Hair Mask. Use 3–9 pumps for the 15 ml mini size, depending on hair length. Wait 4 Minutes: This wait time is critical for the mask to repair the hair's internal structure. Spray AstroLift™: After the 4-minute wait, shake the AstroLift™ bottle well and spray generously throughout damp hair, focusing on the roots. Style: Blow-dry to activate maximum volume, or air-dry for a more natural look.