Obagi Professional-C 20% Serum 30ml

The strongest vitamin C serum Obagi makes. At 20% pure L-ascorbic acid in a stable, low-pH formulation engineered to penetrate the dermis, Professional-C 20% delivers the most potent antioxidant protection and brightening activity available in the range. This concentration sits at the upper threshold of what clinical research shows to be effective for topical vitamin C — beyond which additional concentration yields diminishing returns.

What it does:

• Maximum-strength antioxidant protection against UV-induced free radical damage
• Visible brightening and pigmentation correction, typically from 4 weeks of consistent use
• Stimulates dermal collagen synthesis at the highest effective dose
• Enhances skin radiance, luminosity, and overall tone clarity
• Synergistic protection when paired with broad-spectrum SPF

Best for: Experienced vitamin C users with normal to oily skin who have established tolerance at 10% or 15% and want the maximum clinical benefit. Particularly effective for patients targeting photodamage, stubborn pigmentation, and advanced collagen support. If 20% causes irritation, step back to the 15% formulation.

How to use: Apply 5–7 drops to clean, dry skin each morning. Allow to absorb for 1–2 minutes before layering moisturiser and SPF. Store in a cool, dark place. Discard if the serum turns dark brown or orange.