This elegant serum contains a therapeutic 20% strength of Ester C combined with L-glutathione and amino acids to jointly maintain tissue cellular antioxidants. It also features prized natural moisturizers, hylauronic acid, alpha lipoic acid. This serum will help promote structural soundness, firming, and resistance to sun damage and general signs of aging in the skin. Apply at night. Use jointly with Anti-Aging Serum in a.m.