This is my first vitamin C serum. As I don't have anything to compare it with, I can just say that I like it so far. I use it only at night to make sure I don't get any sun exposure on my skin while I am wearing it. I do like how my skin is a bit more radiant and overall looking a bit better than usual. I will continue using it. I keep it in the fridge as recommended, and I do notice that it takes more than two or three drops to cover my face. Maybe it is because I like to lather my face with products or maybe it is the fact that it is sitting in the fridge before the use, but I still think the bottle will last me a while.