👉 The word 'Olay' refers to an oil that is derived from the skin cells of humans, known as keratinocytes, which are found in the hair, nails, and skin. Definition: Olay is a term used by dermatologists to describe an oil containing keratin, which is extracted from human skin cells. The oil contains active substances such as retinol, hyaluronic acid, and vitamin E that provide nourishment to the skin cells, preventing premature aging. The word 'oily' means heavy or greasy, hence Olay refers to a product with a thick, oily texture.