The Obagi Professional-C Serum 20% is a dermatologist-grade vitamin C serum formulated with 20% L-Ascorbic Acid — the purest and most potent form of vitamin C — combined with Sodium Hyaluronate for added hydration. This fast-absorbing serum is designed for normal to oily skin types and is one of Obagi's bestselling products, recognized with the Allure Best of Beauty Award.

The serum works to brighten and even skin tone, reduce the appearance of dark spots and hyperpigmentation, strengthen the skin's antioxidant defenses, and improve the appearance of fine lines and wrinkles. The high-concentration L-Ascorbic Acid helps neutralize free radicals and combats oxidative stress induced by blue light and infrared radiation that can cause early signs of skin aging. In a clinical survey, 91% of users reported their skin appeared brighter and more hydrated.

Apply 5–7 drops in the morning after cleansing and toning, before moisturizer. Follow with an SPF product before makeup application. Use within 3–6 months of first opening. Store at temperatures not exceeding 25°C (77°F) in a dark, cool place with the cap tightly closed.

Full ingredients: Propylene glycol, aqua/water/eau, ascorbic acid, alcohol denat., ascorbyl glucoside, ethoxydiglycol, sorbitol, sodium hyaluronate, fragrance (parfum), citrus aurantium dulcis (orange) peel extract, citrus paradisi (grapefruit) fruit extract, phenoxyethanol, calcium hydroxide, zinc chloride, citric acid, caprylyl/capryl glucoside, amyl cinnamal, limonene, hexyl cinnamal, benzyl benzoate. For external use only. Avoid contact with eyes, nose, mouth, and lips.