About this item 15% Pure L-Ascorbic Acid Serum: Our Face Serum uses high-purity L-Ascorbic Acid, which is more effective than VC ester.ZealSea L-Ascorbic Acid VC added amount is not only as high as 15%, but also the purity of VC is 100%. The biggest difference is ZealSea Vitamin c Serum can act directly on the skin, no need to transform, easier to absorb than other highly concentrated CE Ferulic serum. Brighten Skin & Correct Dark Spots: ZealSea Vitamin C Facial Serum adopts the most famous Pure L-Ascorbic Acid Vit C + Vitamin E + Ferulic Acid Formula, Dark Spot Serum not only can improve the stability of VC, but also brighten skin, fade dark spots, and anti-oxidant while decrease UV damages and enhance skin elasticity. Repair & Hydrate: Our Blemish Skin Corrector Serum contains Centella asiatica extract to help promote skin cell renewal and sunburn repair, and strengthen the skin barrier. Thanks to sugar isomers, this Vitamin C Serum for Face provides deep and long-lasting hydration. Tips for Vitamin C Facial Serum: For vitamin c beginners, gradually phase into your skincare routine, working up to daily as tolerated.After cleansing and toning,apply 2-3 drops Anti aging Serum to a dry face, neck, and chest,(avoid the eye area)use fingertips to massage until fully absorbed. Storage of Vitamin c serum for face:It is packaged in frosted Glass Bottle packaging which helps not letting light in and slowing down oxidation.For best results,we recommend storing in cool,dry,and dark place,avoid direct sunlight.After opening, the color of vitamin C serum will gradually become yellow, which will not affect the use and effect of the product, which belongs to the normal color range.Do not use it when the color of the Vitamin C serum turns to deep brown.