Containing a high concentration of 22% Ascorbic Acid, 2% Vitamin C Derivative, Ferulic Acid, and Vitamin E, this serum is made water-free so the formula is stable against light and heat, so you don't have to worry about oxidation before the serum runs out. Its main function is to make skin glow brightly, nourish and act as anti-aging. Honestly, when I first started using this serum, there was a slight stinging feeling on my skin, so TIAM said that to make it more gentle, you can mix it with moisturizer, but when I use this serum, I usually skip moisturizer because it's already quite moist. In the afternoon, just add sunscreen. And Vit.C is a super antioxidant, so it works as a booster for the sunscreen that we use. In my opinion, Vit.C is a staple that must be in our skincare range