The serum comes bottled in two parts: There’s a pure 20% L-ascorbic acid powder. And there’s a carefully formulated serum activator that contains soothing, hydrating ingredients along with additional antioxidants. On the hydrating front, you have three different molecular weights of humectant hyaluronic acid to target different layers of the skin. And on the antioxidant front, you have soothing ectoin working synergistically with ferulic acid to help neutralize free radical damage from UV rays and environmental stressors to protect against signs of premature aging.

The amino acid derivative ectoin is an extremolyte (meaning it helps protect cells that exist in extreme conditions). In addition to its antioxidant benefits, it also soothes, supports the skin’s barrier function, and helps prevent transepidermal water loss. We included it in this formula to complement the effects of the vitamin C, which can sometimes be sensitizing. We wanted to create a formula that would be calming and gentle enough for all skin types—without sacrificing an ounce of protective antioxidant power.