Vitamin C (L-Ascorbic Acid)

Vitamin C is the gold standard antioxidant, neutralizing free radicals 50% more effectively than #3 Hyaluronic Acid’s protective claims. L-ascorbic acid at 15–20% concentration boosts collagen synthesis, brightens hyperpigmentation in four weeks, and reduces oxidative stress by 72% in controlled trials. SkinCeuticals’ C E Ferulic serum, priced at $166, consistently commands a loyal following and often sells out within hours of restocking.