Why Glycolic and not any of the other A.H.A.'s?

The family of Alpha Hydroxy Acids (AHA's) includes:

From the above information it can be seen that Glycolic has the smallest molecule size, which makes it best suited for use in skin care. The small molecular size means that it can be absorbed by the skin and enter the ducts, pores and follicles to provide maximum benefit and minimal irritation.

The skin can be compared to a fish net, the openings are only so big, things which are smaller than the openings can pass through and enter, ones larger than the openings are held back. The skin's openings are minute and of all the AHA's it is only Glycolic which can pass through effectively. The larger size of the other AHA's means that they stay on the skin's surface and potentially cause irritation, a fact which does not occur with Glycolic acid, if used properly, and with the correct support products.

Lactic Acid, which at 3 microns in size is only 1 micron larger than Glycolic, is still 50% larger and thus has a much more difficult time passing through, thus decreasing its effectiveness. Glycolic gives maximum effectiveness, due in part to its small molucular size.

This is one of the many reasons why Nancy K. Brown formulates with and encourages the use of Glycolic.