Paula's Choice C15 Super Booster - 15% vitamin c with vitamin e + ferulic acid From Paula's Choice: Our new & improved best-selling 15% vitamin C brightens skin, improves the appearance of fine lines & wrinkles & boosts glow in 15 minutes for immediate results–without irritation. - 15% vitamin C visibly brightens skin -:Ferulic acid & ergothioneine boost visible results - New, gentle formula absorbs quickly for immediate results - Use alone or add to your non-SPF moisturizer or serum