The Dr Barbara Sturm The Good C Vitamin C Serum is a concentrated formula developed to improve luminosity and protect against environmental stressors. Powered by a stable form of Vitamin C, it helps to visibly brighten dull skin, support collagen production and reduce the appearance of uneven tone. The lightweight, fast-absorbing texture delivers antioxidant protection while maintaining hydration, leaving the complexion smoother, firmer and more radiant over time.