The chemical description for the group of acids that includes glycolic, lactic, and malic acid is Alpha Hydroxy Acids, or AHA’s. By far the most commonly used of the AHA’s is glycolic acid. Lactic acid is also an effective exfoliant, but since it is not as popular, partially because glycolic is considered the more effective.  Glycolic is actually the smallest alpha-hydroxy acid and therefore seems to penetrate the best of all the AHA’s. 
 
When you incorporate glycolic acid containing products into your skincare routine, you will generally see improvement in the appearance of fine lines, the tone of the skin, and a lessening in the appearance of pore size.