Chemistry & ProductsQuestion 309 of 484
Among the common alpha hydroxy acids used in chemical exfoliants, which acid has the SMALLEST molecule and therefore the deepest penetration into the stratum corneum?
a.Lactic acid
b.Glycolic acid
c.Mandelic acid
d.Citric acid
Explanation
Glycolic acid has the smallest molecular size of the common AHAs, so it penetrates fastest and deepest. Lactic acid is larger and is preferred when extra hydration is desired; mandelic and citric acids are larger still and act more gently on the surface.
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