Salon Crafted Protein Blends ProteinFusion™ With Biotin, Keratin and Collagen Amino Acids See the Science For Fine & Thin Hair Lift roots, visibly thicken strands, and protect your hair from heat and breakage with this all-in-one leave in spray. Contains our exclusive strand-expanding technology that thickens each strand from root to tip to help create lasting volume and bounce without stiffness or residue.