Our skin's outermost layer has something called an acid mantle, which is made up of the secretions from our sweat glands (the eccrine glands) and our oil-producing glands (sebaceous glands). Researchers have found differences when it comes to the functionality of this skin barrier in men versus women. What does that mean? Men's skin is more acidic than women's skin when rated on the pH scale. The pH scale measures how acidic or basic something is, from 1 (most acidic) to 14 (most alkaline). Water, for example, ranks 7 on the pH scale -- a neutral. Skin pH ranges from roughly 4 to about 7, with the estimated natural skin pH about 4.7 [source: Lambers]. Women's skin averages about 5.6 (± 0.4) compared to the 4.3 (± 0.4) of men's skin [source: Kunin]. Healthy skin has a healthy acid mantle able to control moisture loss and block potentially dangerous microorganisms from penetrating. The healthiest skin also has a pH of just below 5, so daily moisturizing with a pH-balanced product is important in helping prevent moisture loss, increase skin hydration and help keep that barrier healthy.
Not only is a woman's skin slightly more acidic than a man's, it also -- sorry, ladies -- ages faster. In a study published in the journal Optics Letters, researchers have found that women's skin ages more quickly than men's, and this happens not only at the surface, but also within the dermis, the middle layer of skin. Levels of collagen and elastin present in the dermis shrink as we age -- no matter which gender you are, your body just naturally produces less as you age -- but for women the losses begin earlier. Skin begins to thin, become drier and lose its elasticity, and that equals wrinkled, sagging skin. Aging skin is also susceptible to the environment, from humidity to bacterial infections, and can benefit from moisturizers that contain anti-aging and anti-wrinkle ingredients such as alpha-hydroxy acids and ingredients derived from vitamin A.