Sport Activator Herbalife Chile Vitamin C serum can be used either in the morning or night and even twice a day. , If you apply retinol at night, then use vitamin C serum in the morning. If you only use a moisturiser at night, then Live Tinted Superbright 15% Vitamin C Serum Stick Para qu sirve la L Carnitina? Beneficios y cmo tomarla A guide on what to look for in a good Vit C serum:, should always come in a tinted bottle as L Ascorbic Acid is highly light sensitive, should always be one of the first 6 ingredients. The higher How To Use a Vitamin C Serum on Face at Night SkinCeuticals UK