DermaConcepts/ Environ Skin Care Youth EssentiA Vita-Peptide C- Quence Serum 4 Vita-Peptide C-Quence Serum 4 contains an optimum concentration of vitamin A and C that helps combat the visible signs of aging – creating the appearance of even, smoother, and healthier–looking skin. Want to read more? Subscribe to one of our monthly plans to continue reading this article.