Alpha-Hydroxy Acids (AHA) are often found in products claiming to reduce wrinkles or the signs of aging, and improve the overall look and feel of the skin. They are also used as chemical peels available in a dermatologist's office, as well as beauty and health spas and home kits, which usually contain a lower concentration. Although their effectiveness is documented, numerous cosmetic products have appeared on the market with unfounded claims of performance. Many well-known α-hydroxy acids are useful building blocks in organic synthesis: the most common are glycolic acid, lactic acid, citric acid, and mandelic acid.
AHA's are effective in controlling acne, sun damage, and fine wrinkles. They are protective against the effects of the sun (mildly so), and have an anti-oxidant effect. The skin becomes smoother because of the epidermal effect - penetration improves the skin barrier by the protective buildup of the epidermis. Glycolic acid also improves the dermis.
Skin care products containing AHA's can augment AHA chemical peels. The pores become more treatable, and collagen is increased. Whereas TCA (trichloroacetic acid) is cytotoxic (kills cells), the AHA's are not.
Glycolic acid products improve skin tone, giving a smoother feel and a more even skin look. They work for acne, pigmentation, sun damage, and are used as healing agents after cosmetic procedures (e.g., lasers). Glycolic acid products help in bleaching the skin (correcting melasma or brown spots) in combination w hydroquinone or kojic acid, which is more stable than hydroquinone but not as active. To get the best effect for melasma, use of chemical peels in conjunction with products has better results. Glycolic acid is a good adjunct for lasers and other cosmetic treatments.
Glycolic acid is also helpful for psoriasis and icthiosis (dry, thickened, scaly or flaky skin). For sun damage, wrinkles and solar lentigines, it doesn’t work by itself; other products such as Retin-A or retinol are needed for a better effect.
The pH and concentration of the AHAs is important. The higher the pH is better tolerated, but has the same effect as a lower pH. And there is a better effect on the deeper dermal layers with a higher pH and higher concentration.
Bare Skin products containing AHA’s:
Activator
Cranberry Fresh
Enhancer
Night Cream - also contains retinol
Perfect Tone Serum
Rejuvenation serum - also contains retinol
