C.E.O. Brightening Serum.

"This is an $85 vitamin C serum. It's tetrahexyldecyl ascorbate, which is a very good form of vitamin C, but there are other vitamin Cs that have this form of vitamin C that work very well and actually have a light sealed container, whereas this one's just clear glass. I also tried these products—the C.E.O. oil and the C.E.O. cream—and both of them broke me out horribly. I'm a little bit more sensitive to citrus and maybe that's why this broke me out. I just don't recommend this and it's really expensive for what it is. If you are looking for a tetrahexyldecyl ascorbate that's really good and not like $85, The Ordinary has one that's like 10 bucks and I would highly recommend this."

"Sunday Riley C.E.O. Brightening Serum is 15 percent tetrahexyldecyl ascorbate, which is better geared towards those who have sensitive skin and who don't want to use ascorbic acid. It is an extremely runny, lightweight serum, opaque in nature. The texture is beautiful and it does not feel greasy at all. This is one that I do recommend you try if you have sensitive skin and you want to jump on the vitamin C game. It is very nice."