Cosrx as a brand is amazing, and they did not disappoint with this toner! My skin is very sensitive, and as such there are only a few acids I have found that don't irritate my skin. Hyaluronic acid in this product works perfectly to clarify my skin without drying it out or irritating it. The Hydrium Watery Toner is super light, doesn't have much of a scent, and is free from the ingredients that make my skin irritated and angry. It's perfect to use after cleansing just to tone and ensure your skin is grime and oil free before diving into serums! I haven't used this long enough to say for sure, but I have a feeling this is a holy grail product for me!