Trilogy Vitamin C Booster TreatmentTrilogy Vitamin C Booster Treatment Enjoy brighter, more even skin tone fast with our freshly activated 2 week intense brightening serum treatment. It's perfect for use in the lead up to big events or simply to boost tired, dull skin. 71% saw an improvement in skin radiance. Boasting fresh, potent antioxidant vitamin C (6% ascorbic acid), our brightening booster is so active its components are kept separate until you are ready to begin your treatment.