Chemical peels remain some of the most effective, efficient and financially feasible skin care treatments available, and understanding the science behind them allows skin care professionals to most effectively manage, market and take advantage of this powerful, lucrative tool.
Skin, like any material, is subject to wear and tear, chemical and photo degradation, and absorption of chemical pollutants, not to mention microbial invasion. Fortunately, this natural “material” has the benefit of re-building itself through an influx of new cells from the basal layer of the epidermis. However, with age, this constant supply of new cells slows, and a degraded and disorganized skin surface becomes more of the norm. This is where chemical peels—both acid and nonacid—work their magic. Beginning by simply removing the top layer of the epidermis, the skin will exhibit some of its former luster and uniformity, much as the light sanding of an old wooden surface will return some of its finish and surface quality. As a peel works deeper into the epidermis, the lower skin layer loosens and the basal layer of the skin is stimulated to produce new cells. The appearance of new cells can replace aged, oxidized and hyperpigmented skin. The end result is more cellular bulk, offsetting the epidermal thinning that comes with aging; hydrating skin; and improving color uniformity and smoothness.
The most common types of chemical peels are acid peels, which work to remove the cells of the top layer of skin’s upper epidermis by breaking weak chemical bonds that hold together the epidermal skin cells, termed “corneocytes” or “keratinocytes.” Depending on the strength, pH and delivery agent of the peel product, upon application, the skin cells delaminate and lift away. (See Figure 1.) As the peel process proceeds, or upon subsequent treatment, it can penetrate further into the thickness of the epidermis to interact and weaken the bonds holding together the cells of the lower layers of the epidermis.