What Does Glycolic Acid Do to Your Skin?

Glycolic acid is an alpha hydroxy acid used for skin care.

Glycolic acid is a water-soluble natural acid derived from sugar cane. Glycolic acid belongs to the family of organic acids known as alpha hydroxy acids (AHAs). Glycolic acid is used as an ingredient in cosmetic skin care products and for dermatological treatments.

Alpha hydroxy acids include:

• Glycolic acid found in sugar cane
• Citric acid found in citrus fruits and tomatoes
• Lactic acid found in sour milk
• Malic acid found in apples and tomatoes
• Tartaric acid found in grapes

Glycolic acid is a skin exfoliating agent that helps remove the top layer of skin cells including dead skin cells. Glycolic acid helps smooth fine lines and surface wrinkles on the skin, unblock pores and improve skin’s texture and appearance.

Alpha hydroxy acids have been used for skin rejuvenation since ancient times. Cleopatra, the renowned queen of Egypt, is believed to have bathed in sour donkey’s milk to improve her complexion.

Glycolic acid dissolves the proteins that hold skin cells together and promotes the shedding of dead skin cells, exposing the fresher skin that is underneath. The extent of skin peeling depends on the concentration and pH value of the preparations.

Glycolic acid is one of the most common AHAs used in cosmetic products, because it has the smallest molecules among AHAs and can penetrate easily into the skin. Studies have shown that glycolic acid may also stimulate collagen production in the skin and contribute to a firmer skin.

When used on the scalp, glycolic acid may help retain moisture and prevent hair breakage.

The cosmetic use of glycolic acid is primarily to improve skin texture, but it may also be used to enhance absorption of other anti-aging products or acne medications such as retinol. The cosmetic uses of glycolic acid include:

• Exfoliation of the skin
• Clearing acne scars, age spots and fine lines
• Smoothing and making the skin firmer
• Cosmetic products contain 10% or lower concentration of glycolic acid and are available over the counter as:
• Creams or lotions
• Skin toners
• Face washes and cleansers
• Moisturizers
• Shampoos

Glycolic acid in higher concentrations may be used alone or in combination with other medications by medical professionals to treat skin conditions that include:

• Skin aging signs such as discoloration, roughness and wrinkles
• Stretch marks
• Skin damage caused by sun exposure (photoaging)
• Dry skin (xeroderma)
• Skin discoloration (melasma)
• Ichthyosis, a genetic disorder that causes dry, thick scaly skin
• Warts

Glycolic acid may not suit everyone, and some may have reactions. Side effects include:

• Burning
• Rash
• Swelling
• Pigment changes
• Blisters or welts
• Skin peeling
• Itching
• Irritation or tenderness
• Sunlight sensitivity
• Chemical burns

Glycolic acid used in low concentrations as found in cosmetic products are generally safe to use. It may be, however, a good idea to test the product in a small patch of skin before use. If you have any skin condition, check with your dermatologist before using a glycolic acid product.

Glycolic acid increases skin sensitivity to UV rays. When you use glycolic acid products, take care to use sun protection or find products that also contain sun protection. Avoid using other exfoliating scrubs while using glycolic acid.

The Cosmetic Ingredient Review Expert Panel, the cosmetic industry’s self-regulatory body that reviews cosmetic ingredient safety, has determined that a glycolic acid cosmetic product is safe if:

• The AHA concentration is 10% or less
• The final product has a pH of 3.5 or greater
• The final product contains sun protection or has directions on its package that tell the consumers to use daily protection from sun

Under the Fair Packaging and Labeling Act, the FDA requires cosmetic products to have ingredient declaration on the package. Always check the package for ingredients and follow instructions for safe use. Never use products that have higher than 10% glycolic acid, without first checking with your dermatologist.

Skin peel products exclusively used by professionals like beauticians or cosmetologists do not come under the purview of the above act, so concentrations of glycolic acid may go up to 30%. Exercise caution before undergoing such skin peel treatments.

Glycolic acid concentrations of up to 70% are primarily used by doctors for dermatologic treatments and safe when used under medical supervision.