The LA’s peel solution includes (essentially) 14% each of resorcinol, lactic acid, and salicylic acid. Each ingredient performs an important function in the peeling process.

Resorcinol

Resorcinol is a derivative of phenol that has been used as a peeling agent for over one hundred years. It was first introduced for topical application in 1882. In higher concentrations, resorcinol has been shown to cause a separation in the epidermis at the level of the stratum granulosum while inducing an inflammatory response. A relatively low concentration of resorcinol in the LA peel solution is less likely to cause complete exfoliation with a raw surface area. Resorcinol helps to provide a numbing effect and increases the depth of the lactic acid and salicylic acid penetration. Some down time may be associated with re-epithelialization, along with the occurrence of a “resorcinol membrane” or a greyish appearance of the skin approximately 24 hours post-peel. The grey-brown membrane lasts for 2-3 days until visible peeling occurs.

Lactic Acid

Lactic acid occurs naturally in human skin as a part of metabolic processes. Lactic acid in normal skin is partly responsible for maintaining the acid mantle of the skin at a pH of 5.5 to 6.0. Thus, there is no toxicity from the lactic acid itself. It is less irritating than other alpha hydroxy acids and is relatively gentle to the skin.

Several studies have shown that lactic acid has a natural moisturizing effect on the skin. In the 1960’s dermatologists noted that when lactic acid was used in a moisturizer, it enhanced absorption of the moisturizer into the skin. This characteristic enables the lactic acid to work in conjunction with the other two agents to enhance the evenness of the LA peel.

Salicylic Acid

Salicylic Acid penetrates directly into skin follicles, making it a very important component of the LA peel solution. As well as absorbing into the broad skin surface, this acid goes directly into the waxy buildup associated with acne. Salicylic acid unroofs comedones and pustules, opening the sebaceous gland and stimulating the elimination of wastes.

It is necessary to skin test a small area of the inner upper arm prior to applying a full-face peel. A skin test will help to eliminate patients who are sensitive to aspirin.