Retinoid & Vitamin C Serum 1 fl. oz 30 ml with Anti-Aging Peptides - Anti-Aging Night Cream Intense Fine Line & Wrinkle Reducer. Both Retinoid and Vitamin C assist with collagen production and utilization. Because Vitamin C has free radical fighting abilities, it helps protect Retinoid from oxidation so that its anti-aging efficacy does not diminish. This non-irritating dual power combination improved the appearance of fine lines and enlarged pores by penetration deep into the layers of the skin.