Alpha hydroxy acids (AHAs) such as glycolic and lactic acid are water-soluble acids that loosen bonds between surface skin cells, promoting exfoliation, smoother texture, and improved appearance of fine lines and pigmentation. They are commonly used in concentrations from about 5% to 10% in over-the-counter products and higher in professional peels.
| Reported effect | How often | Notes |
|---|---|---|
Skin irritation, stinging, or burning sensation | Common | Most often during initial use or at higher concentrations and lower pH. |
Increased photosensitivity / sunburn risk | Common | AHAs increase UV sensitivity; daily sunscreen is recommended. |
Redness (erythema) and dryness or peeling | Common | Usually mild and transient, more pronounced with frequent application. |
Contact dermatitis | Uncommon | May occur in sensitive individuals or with high concentrations. |
Post-inflammatory hyperpigmentation | Uncommon | More likely in darker skin tones, especially after irritation or peels. |
Blistering, crusting, or chemical burn | Rare | Typically associated with high-concentration peels or misuse. |
Scarring | Very rare | Reported mainly with deep peels or improper application. |
Frequencies reflect typical cosmetic use reported in the literature, not a guarantee for your skin.