I don't know. I can't really pinpoint what specifically this mask does for me when I use it, as I use it on and off in the morning, like every third or second day. I think I like it! I feel like I like my skin better throughout the day when having applied this. I think I notice a glow a few hours after using this! When I have problematic skin days, like my skin is more red and irritated than usual from things like insufficient sleep or even acne, it doesn't really do anything at all to help those things but I don't expect it to. I'm not sure what I'm looking for when using this as I feel as though my skin has enough moisture.

But even using it in place of a moisturiser I don't think this provides enough, I feel a bit naked in my skin when I just use this. I didn't really notice any brightening effects at all having finished an entire bottle of this, maybe I've maximized my brightening potential from the many many  products that I've used in my lifetime. I do really like the ingredients of this mask, the rice extract is really nice and 69% of it is very generous. I'm never surprised with these kinds of things coming from COSRX as they really do care about the ingredients they put into their products. I also like that the hole that the product comes out of is raised so you can swipe away the product and not get any residue that'll dry and build up on the cap.