The Vitamin C 23 Serum

Pure ascorbic acid at 23% leads the formula, with vitamin E and glutathione as partner antioxidants and hyaluronic acid, allantoin, and panthenol cushioning it against dryness. The texture is a slightly viscous serum that spreads thin and settles without stickiness. After cleansing and toning, press in 2–3 drops — many people keep it to evenings at first — and always wear sunscreen during the day. Tingling on application is common and usually fades; if you're new to vitamin C, start with a lower percentage or use this a few nights a week. Don't layer it in the same routine as copper peptides or strong retinoids — split them between morning and evening. Ascorbic acid is fragile: store the bottle in the fridge and use it up within about two months of opening, before the color darkens.