Glycolic Acid
Evidence types available
The smallest alpha-hydroxy acid (AHA) and the one with the deepest penetration. Dissolves the chemical bonds holding dead corneocytes together, accelerating surface cell turnover. Human RCTs show consistent improvement in acne, fine lines, post-inflammatory hyperpigmentation, and textural irregularities. OTC evidence-based concentration: 5–10%. Concentrations of 20–70% are used in professional peels and require careful technique. Photosensitising — always use SPF daily when incorporating AHAs into your routine.
How glycolic acid works in skin
Loosens dead surface cells
Breaks corneodesmosomes at the surface
Smooths texture, fades PIH
Accelerates epidermal turnover
Full cited breakdown coming soon. In the meantime the summary above reflects the current research.