Alpha-hydroxy acids indications and results

AHAs are not toxic to melanocytes, and can therefore be applied on dark skins and in all seasons, on condition that effective sun protection is used. Contact time (Table 8.1) depends on skin type, peel concentration and formulation, its pH, the method of application, preliminary skin preparation, etc. At an identical pH, a 50% concentration of glycolic acid will penetrate half as deep as a 70% concentration, and will take twice as long to do so. 

Condition Glycolic acid concentration (%) Contact time (min) 

The use of AHAs (especially glycolic or lactic acid) in treating acne has often given good or even excellent results. Easy Phytic solution (see Chapter 11) is especially safe, effective and comfortable for this indication. Keratinocyte cohesion 

When treating facial acne, concentrations of 50% or more seem to be the most effective, with contact times of 1-3 minutes. Higher concentrations or prolonged contact times cause unexpected frosting (areas of epidermolysis) and slow down post-peel healing. 

When treating the back, a concentration of 50% is not enough, and concentrations of 70% should be used for 4—10 minutes. If frosting occurs on the back, it is a sign of greater effectiveness, in contrast to facial treatment. Maximum effectiveness is achieved when treating active inflammatory acne. 

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