HISTORY
Glycolic acid, part of the alpha hydroxy acid (AHA) family, boasts a storied history that stretches back to ancient times, with Cleopatra reportedly using AHAs from sour milk to preserve her famed complexion. It wasn't until the 1970s, however, that glycolic acid gained scientific recognition, thanks to Dr. Eugene Van Scott and Dr. Ruey Yu, who identified its exfoliating benefits for reducing fine lines, wrinkles, and acne scars. This discovery led to the creation of various skincare products leveraging glycolic acid's potency.
SCIENCE
Glycolic acid (C2H4O3) is the smallest and simplest AHA, derived from sugarcane. Its small molecular size allows it to penetrate the skin more deeply and easily compared to other AHAs, making it highly effective.
Glycolic acid works by breaking down the bonds between dead skin cells, facilitating their removal. This process reveals fresher, smoother skin underneath and promotes a more radiant complexion. By penetrating deeper layers of the skin, glycolic acid stimulates collagen production, crucial for maintaining skin elasticity and firmness, thereby reducing the appearance of fine lines and wrinkles. Additionally, glycolic acid has humectant properties, attracting and retaining moisture in the skin, helping to keep it hydrated and plump. Regular use of glycolic acid accelerates cell turnover, essential for healthy, glowing skin, which helps fade hyperpigmentation and improves overall skin texture.
Glycolic acid is effective in concentrations as low as 2% for daily use and up to 70% for professional chemical peels. Over-the-counter products typically contain between 5% and 10%, while dermatologist-administered treatments use higher concentrations. The effectiveness of glycolic acid also depends on the product's pH level, with products between 3 and 4 being generally more effective and better tolerated by the skin. Numerous studies have demonstrated the benefits of glycolic acid, including a study published in the "Journal of the American Academy of Dermatology," which found significant improvements in skin texture and reduction of fine lines and hyperpigmentation after a 12-week regimen of glycolic acid treatments.
Glycolic acid is the most researched AHA with proven skin benefits. It helps lift off dead skin cells, stimulates collagen production, and can fade brown spots caused by sun damage or post-inflammatory hyperpigmentation (PIH). Its effectiveness depends on concentration (4-10% for mild daily use, 10-20% for more significant effects, and above 20% for professional treatments) and pH value (best between 3-4). Always use sunscreen when using AHA products due to increased sun sensitivity. Glycolic acid is suitable for most skin types, but those with very sensitive or rosacea-prone skin might opt for milder BHA or PHA products.
REFERENCES
- Tang, S.-C., & Yang, J.-H. (2018). Dual Effects of Alpha-Hydroxy Acids on the Skin. Molecules, 23(4), 863.
- Ditre CM, Griffin TD, Murphy GF, Sueki H, Telegan B, Johnson WC, Yu RJ, Van Scott EJ. Effects of alpha-hydroxy acids on photoaged skin: A pilot clinical, histologic, and ultrastructural study. Pt 1J. Am. Acad. Dermatol. 1996;34:187–195.
- Usuki, A., Ohashi, A., Sato, H., Ochiai, Y., Ichihashi, M., & Funasaka, Y. (2003). The inhibitory effect of glycolic acid and lactic acid on melanin synthesis in melanoma cells. Experimental Dermatology, 12(Suppl. 2), 43–50.