Many facial serum formulations claim to nourish the skin; however, the term has no scientific meaning.
Many facial serum formulations claim to nourish the skin; however, the term has no scientific meaning. Since the product is applied to the non-living stratum corneum, it is not possible to actually nourish the skin. Further, most topical agents are not appropriate for application to the viable epidermis and dermis based on the inclusion of irritating preservatives and emulsifiers. This means the skin cannot practically be nourished externally, only internally. Thus, a nourishing facial serum is a misnomer.
A facial serum is a low viscosity liquid that is applied immediately following washing to a dry face. Serums usually contain a hero ingredient important in skin physiology, such as vitamin C or A. The sera may also contain an ingredient designed to modify cellular functioning, such as a peptide fragment mimicking collagen 1 intending to stimulate collagen production or recombinant epidermal growth intending to stimulate epidermal growth. A moisturizer is then applied over the serum followed by colored cosmetics.
While the word nourishing has consumer appeal meaning something good for the skin or something that enhances appearance, the term makes no scientific sense. Thus, nourishing is the perfect cosmetic word. Regulatory authorities cannot take difference with a word that cannot be defined in a given context. Truly useful cosmetic terms have great consumer appeal while expressing medical nonsense.