All three layers of the skin are constantly undergoing cell turnover, which means the cells are being replaced via mitosis (or cell division). During mitosis, cells make copies of the DNA inside of the nucleus so that when the cell divides there is an identical cell. The process of DNA production requires ATP as a critical component of the DNA helix, but also for the assembly of the helix itself. Mitotic spindles are accessory structures to mitosis and require ATP for their production. Once the cell divides, organelles inside of the cell also require ATP for their production.

All skin cells are constantly trying to maintain homeostasis, which is a requirement for life. Cells have to be able to adapt to changes in their environment, otherwise they are susceptible to damage. Skin cells especially are under constant threats to homeostasis by oxygen radicals, UV damage, chemicals applied to the skin, and physical damage. ATP is the central player in maintaining homeostasis. ATP is used to maintain ion balance across cell membranes, produce proteins, lipids, carbohydrates, and nucleic acids to counteract damage.

All skin cells are constantly sending out messages to other cells and also sending messages inside of cells to control structure and function. ATP plays a key role in cell-to-cell signaling by production of the signaling molecules and also the vectors that sometimes encloses the signaling molecule. In internal cell signaling, ATP plays a key role in the phosphorylation of proteins and enzymes that control molecular pathways.

Cells that reside within the skin produce trophic factors (growth factors, mitotic factors, cytokines, chemokines) that are responsible for controlling cell growth.

In healthy skin, there are proteins and proteoglycans that are produced by fibroblasts and other cells that help maintain the structure and suppleness of skin. Fibroblasts make two central proteins in the skin architecture; collagen and elastin. The balance of these two proteins is determined by the levels of ATP in the skin. As the skin ages, it begins to lose mitochondria as a result of decreased dermal blood flow, thus reducing the production of ATP.

As we age, this decrease in fibroblast ATP levels affects the turnover of collagen and elastin, resulting in a shift towards more collagen and less elastin. This transition leads to the skin losing tone and becoming wrinkled.

Skin cells use oxidative phosphorylation to produce large quantities of ATP. However, the production of ATP by this mechanism results in the production of an oxygen radical. In normal skin, the radical is reduced by antioxidants, but in aged skin the ability to capture the radicals is reduced and damage occurs. Applying ATP topically decreases the reliance on oxidative phosphorylation. Furthermore, ATP is important in the production of antioxidants.

The epidermis of the skin helps control water loss, and to prevent substances and microorganisms from entering the body. The kertinization of epidermal cells and transition from living cells to fully kertinized cells requires ATP. ATP is involved in the production of keratin and ATP is involved in the degradation of internal structures of the cell that are removed to as the cell keratinizes.