The Powder That Outlasted a Decade of Serums

Harper's Bazaar's beauty desk has spent years testing vitamin C serums that promise dramatic brightening and mostly fall short. The one formula the magazine says has actually held up isn't a serum at all — it comes as a powder. That a powder outperformed the liquids the category is built on is the kind of small, useful correction that comes only from having tried the rest first.

With reporting from Harper's Bazaar.