Obagi Medical | Professional-C Serum 15%

What It Is:
Made with 15-percent pure L-ascorbic acid—the industry's gold standard of vitamin C—this powerful daily antioxidant serum helps defend skin from free radicals while working to brighten skin tone and reduce signs of past damage.

Editor feedback:
“So many derms recommend this powerful, glow-inducing serum, and for a good reason: It works.” —Liz Ritter, executive editor

How to use:
Apply five to seven drops in the morning after cleansing and toning, before moisturizer, and follow up with SPF before makeup application.

Key ingredients:
The star of this product is 15-percent L-ascorbic acid, which is the most bioavailable form of vitamin C that helps to neutralize free radicals, minimize the look of fine lines and wrinkles, and brighten skin tone.