Alpha hydroxy acids act as chemical exfoliants, which help to loosen and get rid of the dead skin cells on your skin’s surface. The acids are more effective than abrasive exfoliants, such as scrubs and cloths, according to the Harvard Medical School. Regular exfoliation helps keep your complexion naturally bright by preventing a buildup of dead skin cells that dull your skin. There are different kinds of AHAs; Some examples are glycolic acid, lactic acid, mandelic acid, etc) (Further Reading: All About Skincare Acids)
Alpha Hydroxy Acid (AHA) are acids derived from natural substances such as sugar cane, milk, grapes etc. They work by melting the intercellular glue that holds our skin cells together. AHA’s are water loving and water soluble acids and their molecular structure is small. AHAs are preferred for sun-damaged and dry skin because they exfoliate on the surface of skin and have the added benefit of also improving moisture content. A main point of difference is that they don’t penetrate as deep as BHA and the effects are felt on the surface of the skin. AHA’s are great to rejuvenate aging skin.
On the other hand, Beta Hydroxy Acid (BHA) is an oil loving acid.