Optimum repair serum is made with small molecular Hyaluronic acid, patent Peptide and Hydrolyzed micro-collagen/ small molecule from fish skin. A special penetrating agent ( palmitic acid) is added into the serum to increase skin cell proliferation and adhesion which result in improved skin thickness and tonicity. Improves hydration, plumps and restore skin volume. " I tried many facial serums some very pricy with pleasant feeling but no efficacy. I use Optimum repair serum with HPcream and winter with the caviar and truffle Bio-Cell cream. With Biotec USA you get not just the best quality and value but best education. The science director does not sugar coat science but she just deliver it in a bottle." Petya Balevska Maryland