What is a serum?
A SKINCARE serum is a thick liquid-like, (generally) oil-free product with a high concentration of active ingredients and is often moisutrizing, although is not necessarily a moisturizer. They are often used after cleansing and before applying moisturizer or night cream as a sort of supplemental product. They’re commonly used in targeted skincare for anti-aging, anti-oxidation, hydration and plumping, brightening, evening skin tone and to help with acne. Some claims say that the molecules in serum are smaller than in lotion therefore they penetrate the epidermis (top layer of skin) more readily and quickly, but I haven’t found scientific evidence to back-up that claim.
Generally speaking, cosmetics companies are free to use the term however they please (there’s no regulation) but this is the general lay person’s definition of a serum versus, say, a day cream or face balm.
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