Vitamin C is the best-known antioxidant in skincare — in CosIng, the official EU ingredient database, antioxidant is the first registered function of ascorbic acid. Korean brands rarely bottle the pure form as is: to keep the fragile molecule working they either encapsulate it or choose gentler derivatives such as 3-O-Ethyl Ascorbic Acid. Beauty of Joseon takes the derivative route in its centella and Vita C serum and says openly it was formulated to be gentle enough for sensitive skin; Medicube seals stabilised liposome vitamin C into golden capsules together with ferulic acid and vitamin E; Missha builds its brightening toner on a vitamin C liposome and adds PHA for mild exfoliation.
The shared promise is an even, radiant tone. Mary&May states that vitamin C in its sheet mask suppresses melanin production and pairs it with niacinamide, which blocks the transfer of melanin; Skin&Lab surrounds concentrated vitamin C with a 15-vitamin complex, five types of hyaluronic acid and panthenol so the serum brightens without dryness.
Two usage rules repeat across official brand pages. Vitamin C and sunscreen are a pair: Beauty of Joseon tells you to wear its serum under sunscreen during the day, and Medicube advises finishing every morning routine with SPF. And do not layer it with AHA/BHA/PHA acids in the same routine — that caution comes from Beauty of Joseon directly.
Pick the format by its role: a serum for focused work on tone, a capsule cream for the evening, a toner for the lightest daily dose, patches and masks for a quick boost.
For the full picture — pure ascorbic acid vs derivatives, the layering order and the SPF rule — read our vitamin C guide.
