AHA, BHA and PHA.. what are they and what is the difference?

AHA (alpha hydroxy acids) are acids that are derived from fruits, nuts, milk or sugars. They are hydrophilic (attracted to water) and break down the bonds between cells (desmosomes) to allow for easier exfoliation. The most commonly used AHA are:

glycolic acid (derived from sugars) is degreasing and is effective for controlling sebum production.

malic acid (derived from apples) is hydrating, soothing and increases tissue respiration.

tartaric acid (derived from grapes) is antioxidant.

mandelic acid (derived from bitter almonds) helps control pigment.

citric acid (derived from citrus fruits and corn) is anti-aging, brightening and increases epidermal thickness.

lactic acid (derived from milk and sugars) is antimicrobial, hydrating, inhibits pigment and adjusts pH.

Alpha hydroxy acids are commonly used in skin care to brighten the skin by increasing exfoliation. Citric and lactic acids are beneficial in that they are both biocompatible and have multiple benefits.

 BHA (beta hydroxy acids), the most common of which is salicylic acid, is derived from willow tree bark, wintergreen oil or sweet birch. Because salicylic acid is lipophilic (attracted to oil) and keratolytic, it is able to penetrate the oils in the skin and clear out follicles of excess debris and skin cells, making it especially effective in  the treatment of acneic skin conditions.

PHA (poly hydroxy acids) function the same as AHA, but cause less irritation due to their larger molecular size. They are especially beneficial in treating sensitive skin types that may not be able to tolerate AHA.  They provide anti-inflammatory and antioxidant benefits as well as assist with exfoliation. Some common PHA are:

 lactobionic acid (derived from lactose found in cow’s milk) is humectant, antioxidant and soothing.

galactose is a sugar utilized in glycosaminoglycan and collagen synthesis, and cell migration, which may enhance wound healing.

gluconic acid (a naturally occurring ingredient in cells), also known as gluconolactone in skin care products, is antioxidant and anti-inflammatory, while possessing AHA properties

 AHA, BHA and PHA are beneficial ingredients to the skin and can be found in many PCA SKIN daily care and professional treatments.  When used in harmony, they can be beneficial to all skin conditions and skin types.