alpha-hydroxy acid 
noun Chemistry
An organic acid containing a hydroxyl group bonded to the carbon atom adjacent to the carboxylic acid group. A number of such compounds are used in skincare preparations for their exfoliating properties.Chemicals related to vitamin A such as tretinoin (eg Retin A cream) and chemical peels containing alpha-hydroxy acids (eg glycolic and lactic acids) are commonly used for this....
- Nonchemical exfoliators such as alpha-hydroxy acids and beta-hydroxy acids loosen dead skin cells so they slough off more efficiently.
- Exfoliating scrubs and chemicals like alpha-hydroxy acids and retinoids (including retinol, Retin-A and Renova) can leave skin smooth and glowing because they eliminate dull, dead cells on the skin's surface.