vitamin c serum 20% pure l-ascorbic acid, ferulic acid, vitamin e and hyaluronic acid for face and eyes natural anti aging anti wrinkle 1oz. by dr. brenner (1 oz) dr. brenner our vitamin c serum is made with 20% pure vitamin c (l-ascorbic acid), 1% vitamin e (alpha tocopherol), 1% hyaluronic acid (sodium hyaluronate), and 0.5% ferulic acid, our formula improves signs of aging and sun damage, the appearance of lines and wrinkles, and the loss of firmness, while brightening skin's complexion.