Obagi Professional-C 20% Serum 30ml

Maximum strength 20% vitamin C serum, best suited to normal and oily skin. It is the highest concentration in the Professional-C range, and it is a step up for people already using vitamin C comfortably rather than a starting point.

Apply four to five drops to clean, dry skin in the morning, then moisturiser and sunscreen. Higher is not automatically better with L-ascorbic acid: above roughly this concentration the benefit plateaus while the sting does not, so if it tingles for more than a minute or leaves your skin pink, the 15% will serve you better. Dry and sensitive skin should start lower. Keep the bottle closed and out of the light.