Alpha Hydroxy Acid (AHA)

LadyQuestionMarksAlpha Hydroxy Acids (AHAs) are a group of natural acids found in foods. AHAs include Glycolic acid found in sugar cane, Lactic acid found in sour milk (Cleopatra’s AHA of choice), Citric acid found in citrus fruits, malic acid found in apples, Tartaric acid found in grapes and others.

Glycolic Acid is the most active and beneficial of the AHAs due to its small molecular size and is most frequently found in skin care products. Once applied, glycolic reacts with the upper layer of skin, weakening the structures that hold the dead skin cells (corneocytes) together. This allows the outer skin to “dissolve” and allows the new, refreshed, unblemished skin to shine through.

Because it penetrates the skin so rapidly, glycolic acid may occasionally irritate sensitive skin. This occurs as a stinging, burning or itching sensation that may cause those who experience it to discontinue use and miss out on the rejuvenating benefits of the product.

AHAs and BHAsAHA’s also stimulate the growth of elastin and collagen, both which become depleted with age. This allows skin to become healthier, more resilient and thus reduces the formation of wrinkles.

Best uses for AHAs: Treating dull, dry, sun damaged, skin

Beta Hydroxy Acids (BHA)

Beta Hydroxy Acids (BHAs) are another class of compounds commonly used in skin care products. The best-known BHA is salicylic acid. Most often, BHAs are used for people with acne-prone or oily skin types because of the excellent penetration into the pores, removal of blackheads and reduction of oil on the surface of the skin.

The main difference between alpha hydroxy acid and beta hydroxy acid is their lipid (oil) solubility. AHAs are water soluble only, while BHAs are lipid (oil) soluble. This means that BHAs are able to penetrate into the pore which contains sebum (oil) and exfoliate the dead skin cells that are built up inside the pore. Because of this difference in properties, beta hydroxy acid is better used on oily skin with blackheads and whiteheads.

BHA appear to be less irritating than AHA even though it penetrates deeper into the pore. This occurs because salicylic acid is derived from acetylsalicylic acid, or aspirin. Aspirin has anti-inflammatory properties, and salicylic acid retains many of these anti-inflammatory properties. Despite this fact, BHA can still cause skin irritation. Symptoms of irritation include redness, burning, itching, pain, and possibly scarring. People with darker coloured skin are at a higher risk of scarring pigment changes with beta hydroxy acid.

Beta hydroxy acid works best in a concentration of 1% to 2% and at a pH of 3 to 4.

Best uses for BHAs: Treating oily, acne prone skin, blackheads and white heads

While both AHAs and BHAs may be able to reverse some of the damage caused by photoaging (sun exposure) it simultaneously makes skin more susceptible to photoaging. In some people, this sun sensitivity can increase by as much as 50 percent.

If you’re going to use either type of hydroxy acid, be sure to discuss with your skin care provider how to best use it for your skin. Remember to always, always wear sunscreen! Plenty of it and always re-apply!