Hormones are chemical messengers, secreted by glands, that direct the function of various processes in your body, such as growth and development, metabolism, sexual function, mood and reproduction. You are at your most fertile during your 20's and early 30’s. From your mid-30’s onwards, fertility drops off until menopause. So, even before menopause, as we age, estrogen levels will start to decline and, as estrogen is in every cell of the body, this can also have an impact on skin health.