The type of vitamin C matters, too. Ibrahimi advises to choose a vitamin C serum made with L-Ascorbic acid, since it’s an active form of vitamin C. Keep reading for our favorite vitamin C serums ...

Of all the vitamin-C options, our experts generally recommend looking for serums that contain ascorbic acid, also known as L-ascorbic acid, which is the most active and purest form of vitamin C.

Also known as ascorbic acid, vitamin C is a small carbohydrate molecule first identified in the 1920s by Albert von Szent Györgyi, who discovered that it was able to prevent and cure scurvy.