Complex C Serum– Designed for use by all skin types. If using with Alph or Beta Hydroxy Acid products or retinols, use Complex C serum first. This serum can be used under your daytime or nighttime moisturizer. If only using one time per day, use in the morning to maximize the antioxidant protection. This complexed Vitamin C serum will protect, hydrate and condition the skin. Will assist in the healing of acne lesions. Vitamin C helps protect the skin against pollution and environmental assault.