Glossary
A family of water-soluble acids derived from natural sources (milk, sugarcane, fruits) that exfoliate the skin by dissolving the bonds between dead surface cells. Common AHAs include glycolic acid, lactic acid, and mandelic acid.
Alpha hydroxy acids occur naturally in many foods: glycolic acid in sugarcane, lactic acid in milk, malic acid in apples, tartaric acid in grapes, and citric acid in citrus fruits. Cleopatra reportedly bathed in sour donkey milk, which is rich in lactic acid, for its skin-smoothing effects. Modern skincare has refined these natural acids into precisely concentrated products, but the fundamental chemistry is ancient.
AHAs dissolve the desmosome bonds (protein "rivets") that hold dead skin cells together on the skin's surface. By weakening these bonds, AHAs allow dead cells to shed more efficiently, revealing the smoother, more evenly pigmented cells beneath. At higher concentrations and lower pH levels, AHAs also stimulate collagen production in the dermis and increase skin hydration by drawing water into the epidermis.
Glycolic acid has the smallest molecular size, penetrates deepest, and is the most potent. Lactic acid is larger, gentler, and doubles as a humectant, making it better for sensitive and dry skin. Mandelic acid is the largest and gentlest, suitable for sensitive skin and dark skin tones where overly aggressive exfoliation can trigger hyperpigmentation.
Gluconic acid, produced by glucose oxidase in raw honey, is a mild AHA. When you apply raw honey as a face mask, the gluconic acid provides gentle chemical exfoliation while the honey simultaneously moisturizes. The concentration is lower than a dedicated AHA product, making it suitable for sensitive skin that cannot tolerate higher-strength acid treatments.
For most people, 2 to 3 times per week is sufficient for leave-on AHA products. Daily use is possible with lower concentrations (5% or less) once the skin is acclimated. Over-exfoliation with AHAs causes redness, sensitivity, and barrier damage. AHAs increase sun sensitivity, so daily SPF is mandatory during use.
Raw honey contains gluconic acid, a mild AHA produced by its glucose oxidase enzyme. Applied as a mask, honey provides gentle chemical exfoliation at a lower intensity than dedicated acid products, making it suitable for sensitive skin.
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