Are lactic acid and glycolic acid the same?
Both are alpha hydroxy acids. However, lactic acid is the only alpha hydroxy acid that occurs as a natural human metabolite – it occurs naturally as a very essential part of the human metabolic system and, as such, is actually produced by our bodies in the metabolism of glucose under certain conditions. Therefore, lactic acid has no toxicity in humans. Although lactic acid and glycolic acid both have similar characteristics that cause exfoliation, lactic acid is a three-carbon chain, whereas glycolic acid is a two-carbon chain. Therefore, due to the smallness of the glycolic acid molecule, it reacts more rapidly, is usually harsher and more irritating to the skin, and thus more likely to cause unwanted complications.
