The creams should be used immediately after being made. Your active ingredients are more effective when the formula is freshly made: the encapsulated hyaluronic acid contained in the moisturizing bases will be activated upon application. The power of thermo-cosmetics will be turned on optimizing a better distribution of the cream on the skin, better absorption of active ingredients and a better sensory experience. LimeLife for DuoLab formulas are made without preservatives. They are therefore vulnerable to contamination once the face care dose has been freshly made.