The pH of the skin of children is closer to neutral (pH 7). At puberty, however, began to produce more hair on the body. Hair follicles have an associated sebaceous gland or glands which become active as hair growth increases, causing changes in the pH of the skin. The hormones that control sweat also activated and all surface of the skin of a teenager is totally different from a toddler. This is how our body to increase our defense system. The pH of normal skin, healthy human is between 4.5 and 6.

However, this varies with age. Typically, newborns have a pH near neutral (pH 7), which quickly turns sour, to protect the skin of young children. In the late teens to early 20s our Acid Mantle is well developed and provides good protection against potentially harmful external factors of the environment. Our skin looks healthier, heals quickly when injured and seems to take care of itself. With increasing age however, the pH of the skin becomes more and more neutral, and therefore more susceptible to bacterial growth. This reduced acidity kills fewer bacteria than before, leaving skin susceptible to bacterial growth and infection. The skin weakens as a result and start to have problems with age. (Interestingly, the pH value rises beyond 6 when a person is really a skin problem or skin disease.) The aging of the skin causes biochemical changes in collagen and elastin, connective tissue underlying the skin, which give skin its strength (collagen) and elasticity (elastin).