The Quintessential Serums are the purest formulations in the Biologique Recherche range. Their only active ingredients are amino acids or short peptides and a bare minimum of preservatives. They are designed to treat specific skin imbalances (dehydrated, devitalized, lined and/or seborrheic skin, etc.). The serums can be used alone, or mixed together. Remodeling Face Machine can be used to optimize their effect during treatment in a beauty institute.