AHA Alpha hydroxyl Acid
Acronym for alpha hydroxy acid. AHAs is derived from various plant sources or from milk. However, 99% of the AHAs included in cosmetics are synthetic. In low concentrations (less than 3%) AHAs works as water-binding agents. At concentrations over 4% and in a base with an acid pH of 3 to 4, these can exfoliate skin cells by breaking down the substance in skin that holds skin cells together.
AHAs is widely used for therapy of photodamaged skin, and also has been reported to normalize hyperkeratinization (over-thickened skin) and to increase viable epidermal thickness and dermal glycosaminoglycans content. AHAs exfoliates sun-damaged skin from the surface of the skin. Other affects of AHA are Skin appears more youthful, smoother and satiny. Lines and wrinkles are softened; pigmentation spots lightened. For any topical compound, including AHA, it must penetrate into the skin where it can act on living cells. Bioavailability (influenced primarily by small molecular size) is one characteristic that is important in determining compound's ability to penetrate the top layer of the skin. Glycolic acid having the smallest molecular size is the AHA with greatest bioavailability and penetrates the skin most easily; this largely accounts for the popularity of this product in cosmetic applications.
Dermal effects: AHAs with greater bioavailability appear to have deeper dermal effects. Glycolic acid, lactic acid and citric acid, on topical application to photo damaged skin, have been shown to produce increased amounts of mucopolysaccharides and collagen and increased skin thickness without detectable inflammation.
AHAs is widely used for therapy of photodamaged skin, and also has been reported to normalize hyperkeratinization (over-thickened skin) and to increase viable epidermal thickness and dermal glycosaminoglycans content. AHAs exfoliates sun-damaged skin from the surface of the skin. Other affects of AHA are Skin appears more youthful, smoother and satiny. Lines and wrinkles are softened; pigmentation spots lightened. For any topical compound, including AHA, it must penetrate into the skin where it can act on living cells. Bioavailability (influenced primarily by small molecular size) is one characteristic that is important in determining compound's ability to penetrate the top layer of the skin. Glycolic acid having the smallest molecular size is the AHA with greatest bioavailability and penetrates the skin most easily; this largely accounts for the popularity of this product in cosmetic applications.
Dermal effects: AHAs with greater bioavailability appear to have deeper dermal effects. Glycolic acid, lactic acid and citric acid, on topical application to photo damaged skin, have been shown to produce increased amounts of mucopolysaccharides and collagen and increased skin thickness without detectable inflammation.
