Glycolic Acid is an alpha hydroxy acid (AHA), a group of chemicals that are also known as fruit acids and are most commonly used in the form of chemical peels and anti-aging skin products. Industrial uses for glycolic acid are for removing rust and degreasing and therefore require high concentrations over 70% or more. These concentrations are considered to be very dangerous to exposed skin. Glycolic acid is also used as a tanning and dyeing agent in the textile industry and sometimes as a flavoring agent in food processing.
Since glycolic acid is derived from sugar cane, it is considered a natural chemical and as a milder acid, is generally safe for personal use. There are other fruits from which glycolic acid can be extracted such as pineapples, unripe grapes, cantaloupe and sugar beets. Because glycolic acid so easily penetrates and reacts with the epidermis, it functions as an exfoliant or a pH adjuster (a buffer) in many skin care products.
Glycolic acid is a natural exfoliant in its removal of dead skin cells, is a natural skin brightener and has many anti-aging benefits including removal of skin discoloration. When applied to the skin, glycolic acid reacts with the upper layer of the epidermis by weakening the binding properties of the lipids holding the dead skin cells together. This reaction “dissolves” the outer layer of the skin and reveals the underlaying skin which has a smoother, unblemished, youthful appearance. Due to its powerful reaction to skin, the concentration levels of glycolic acid in skin products are generally restricted to low levels. If skin peels and exfoliants are used too often, they can have corrosive effects to the skin and is why it’s recommended for use only once or twice a week.
The EWG’s Skin Deep database lists glycolic acid with a score of 4 based on overall hazard and use restrictions.