Adding this Philosophy Turbo Booster C Powder ($39) to a serum like The Ordinary Pycnogenol, is one of my favourite powerful, all-over treatments for hyperpigmentation. This vitamin C powder can technically be added to any serum, moisturiser, or regular eye cream to give skin a brightening boost. (I would avoid combining it with anything including niacinamide which can make vitamin C less effective and potentially irritate sensitive skin.)