Kylie Skin Vitamin C Serum ($28) is a lightweight serum that uses vitamin C to brighten and tone skin. On the days that we used the serum, it did exactly that (though, it was hard to gauge if the effects were long-term). The liquid quickly absorbed onto skin.
Bhanusali called out its use of ferulic acid. "It's an underutilised antioxidant," which is known to fend off free-radical damage, he said.