Estrogen-The skin thins out at the beginning of the menstrual cycle when estrogens are lowest, and thickens as estrogen rises. This same phenomenon is true during peri-menopause and menopause when estrogen is at its lowest. Estrogen does not only produce hyaluronic acid, but also, there is scientific evidence that skin aging can be significantly delayed by the supplementation of estrogen. It improves the skin’s extracellular moisture content responsible for its tone and appearance. Estrogen also improve the collagen content and quality of skin.