Its a nice serum, leaves a little bit of a sticky residue. 

To be honest I haven't seen a big difference in the brightening effect, but I need to use it a bit more diligently to see results. 

Good product. I will buy it again.

This product has been talked about a lot in the beauty community and I see why. It is an excellent vitamin C serum. My advice is to use this right away. I bought a back up of this and left it stored for a while, when I opened it sadly it has gone bad so you have to be careful and follow the storage instructions.