Glycolic acid (AHA)

Glycolic acid is one of the ingredients belonging to the group of alpha hydroxy acids (AHAs), which are used in cosmetics for chemical exfoliation. In recent years the chemical exfoliation trend has replaced old-fashioned mechanical scrubs/peels whose particles are mostly too rough for the delicate skin of the face. Glycolic acid functions as an exfoliator in such a way that it softens on the chemical level the surface dead skin cells which are invisible to the eye and gently removes them from the skin, leaving it refreshed. With years, the speed of natural turnover of dead surface skin cells reduces, so mature skin is visibly more grey, tired and lifeless in comparison to young skin which has a natural luminosity and healthy colour.

Glycolic acid has the smallest molecular structure among AHA exfoliators which enables it to penetrate deeper into the dermis making this type of alphahydroxy acid very effective in treating a wide spectre of dermatological disorders. Yet, it is most often indicated for prompting collagen production, evening out and refreshing skin tone and retexturing the skin, whether it is marked by wrinkles or large pores (source: Kim S.J., Won Y.H. 1998 The effect of glycolic acid on cultured human skin fibroblasts: cell proliferative effect and increased collagen synthesis Journal of Dermatology, 25:85-89.)

Even though it is most well-known as an “anti-age” ingredient, glycolic acid is an acid which is also especially effective for skin that suffers from abnormal skin keratinisation and increased sebum production (which is evident from the appearance of pesky comedones and constantly “clogged” pores).

In order for it to be efficient as an exfoliator, glycolic acid must be placed in an acidic pH medium (up to pH 4). Further, the strength of the exfoliating effect on the skin will depend on the glycolic acid’s concentration. The greater the concentration of glycolic acid and the more acidic the pH medium in which it is found, the greater the effect of the product will be on the skin. Unfortunately a stronger effect in this case does not necessarily mean a better effect since skin which is exfoliated too often or too intensively has a weakened hydrolipidic barrier, meaning that it may become more sensitive to negative effects from the environment such as UV radiation, and to frequent irritants in skincare which may lead to secondary inflammatory processes.

Glycolic acid efficiently accelerates restoration of the skin’s surface layer so that, just like with other AHA and BHA exfoliators, in the first couple of weeks of use it may bring to the surface spots and comedones which would have quickly surfaced on their own. This is a completely expected although somewhat annoying side-effect of using acids. The skin is “re-learning” the speed of natural exfoliation. Already after first use, it is evident that the skin is becoming more luminous, healthier and fresher yet, just as with any other active substance, only continued use on a daily or weekly basis (depending on the strength of the exfoliator) will give a permanent effect. Two Skintegra products are formulated based on glycolic acid: Lumion for all skin types and Clarion for oily and combination skin prone to acne and comedones.