FUNCTION
Glycolic acid (GA), extracted from sugarcane, is one of the most widely used alpha-hydroxy acids in dermatology, especially for chemical peels. Its small molecular size allows it to penetrate the skin efficiently. Its versatility makes it suitable for various peel intensities, each offering distinct skincare benefits.¹
The strength of a glycolic acid peel depends largely on the concentration of GA used. Higher concentrations result in more intense peeling effects but must be carefully managed to prevent over-exfoliation or skin damage.²
In 2009, Fabbrocini et al. classified glycolic acid peels based on concentration and application duration, categorizing them as very superficial, superficial, and medium depth. Very superficial peels (30%-50% GA) are applied for 1-2 minutes, providing gentle exfoliation with minimal downtime. Superficial peels (50%-70% GA) are left on for 2-5 minutes for a deeper exfoliation, while medium-depth peels (70% GA for 3-15 minutes) reach further into the skin layers, delivering more significant rejuvenation.³
GA peels are valued not just for their exfoliative properties but also for their soothing, keratolytic, and antioxidant effects. The mechanism of action involves breaking down the corneosome, decreasing its cohesiveness and promoting desquamation, which sheds dead skin cells and promotes smoother, more radiant skin.¹
Proper neutralization is crucial after GA application to halt the acidification process and prevent excessive irritation or damage. Pre-peel priming with agents like tretinoin, kojic acid, or hydroquinone is especially important for patients with darker skin tones, who should avoid certain treatments a week prior to the peel to reduce the risk of hyperpigmentation or scarring. Post-peel care includes avoiding sun exposure and exfoliating products, as well as applying sunscreen and moisturizer to aid skin healing. When performed correctly, GA peels are safe, with no systemic toxicity, and can be combined with other treatments for enhanced cosmetic results.¹
DERMATOLOGICAL APPLICATION
Glycolic acid is used in chemical peels to address several dermatological conditions, including acne, acne scars, melasma, post-inflammatory hyperpigmentation, photoaging, and seborrhea. Studies show that GA can help manage acne by normalizing keratinization and increasing the expression of hyaluronic acid and collagen in both the epidermis and dermis. ¹,⁴ This dual action not only improves skin texture but also enhances hydration and promotes skin healing, making GA a versatile option for both skin rejuvenation and acne management. Additionally, its ability to accelerate skin cell turnover makes GA an effective treatment for pigmentary disorders such as melasma and post-inflammatory hyperpigmentation, while its keratolytic properties help reduce seborrhea and enhance overall skin clarity. Recent research also suggests that glycolic acid may support skin barrier function by promoting ceramide synthesis, further improving the skin’s ability to retain moisture and defend against external aggressors.⁵
