The most common chemical agents currently used for medium-depth peeling are 70% glycolic acid and 35 to 50% TCA, with or without adjuvant combination products (e.g., Jessner’s solution [comprising 14g resorcinol, 14g salicylic acid, 14mL lactic acid in ethanol constituted to 100mL] or solid carbon dioxide [CO2]). 2 , 3 , 5 , 7 – 9 , 15 , 19 – 23 In addition, multiple layered applications of 20 to 40% salicylic acid and pyruvic acid are also used for medium-depth peeling, though not traditionally considered medium-depth peels. If you’re less concerned about acne or wrinkles but find yourself with pesky dry patches or unevenness that you’d like to treat, consider glycolic acid an easy ally to the cause. The GA peel is time-tested. Proper selection of patients, timing of peel, and neutralization on-time should ensure good results and no side effects. Superficial peels using alpha-hydroxy acids increase the epidermal activity of enzymes, leading to epidermolysis and exfoliation. 10

CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you. Berardesca E, Distante F, Vignoli GP, et al. Alpha hydroxyacids modulate stratum corneum barrier function. Br J Dermatol 1997;137:934-8. View abstract. Glycolic acid’s efficacy is based on the concentration and frequency of use, but another important consideration is combination therapy, as adding another topical or professional treatment can yield greater results. Glycolic Acid ProductsAs with all acids, glycolic comes with some baggage. And due to its low molecular weight, incorrect use can actually prove more problematic than it might with other AHAs. Dr Zamani says: “Overusing glycolic acid can leave the skin red, dry and more sensitive to the sun. This can cause premature ageing, thinning of the skin and heightened risk of pigmentation.”

Of the AHAs, glycolic is the simplest in structure and the smallest,’ says Dr Rekha Tailor, cosmetic doctor and skin specialist at Health and Aesthetics Clinic. ‘It has the lowest molecular weight, which means that it can easily permeate the skin. Glycolic acid exfoliates the outermost dead layer of the dermis and increases luminosity by improving the reflection of light on the skin.’Conventional exfoliants increasingly seem old-fashioned, as the popularity of at-home chemical exfoliation increases. Of the wide range of acids now available, many are kind enough to exfoliate with at home, and glycolic acid is one of the most popular. If you're just starting to incorporate glycolic acid into your skincare regimen, I would suggest using a gentle glycolic cleanser to get your skin used to it, rather than diving straight into a leave-on glycolic product,’ suggests Dr Tailor. ‘Glycolic acid is most effective when administered as a chemical peel by your cosmetic doctor – they utilise stronger ingredients for more potent effects.’

Lactic acid, which is structurally identical to glycolic acid with the exception of an additional methyl group at the β-carbon end, has a lower pKa and thus a lower pH than glycolic acid at equivalent concentrations, allowing for efficient chemoexfolation at lower concentrations. 35 – 37 , 40 Clinically, lactic acid has demonstrated comparable efficacy in the treatment of photodamage, superficial hyperpigmentation, and fine rhytides compared to standard glycolic acid peels.Because lactic acid has a lower pH than glycolic acid, a lower concentration is often used to achieve an equivalent depth of keratocoagulation compared to glycolic acid, which allows a favorable side effect profile and recovery time. As with glycolic acid, neutralization is necessary, and exfoliation after treatment typically occurs over several days with complete reepithelialization in 7 to 10 days. 1 , 2 , 17 , 27 , 28 , 39 In 15 cases of melasma (epidermal: 80%; dermal: 13.3%; and mixed: 6.6%), 52.5% GA concentration was applied for 3 minutes. There was good to fair response in patients with epidermal and mixed melasma, while no significant improvement was seen in dermal melasma. 24

Can you use glycolic acid with retinol?

Skin imperfections can be caused by bacteria on the skin. 3 Glycolic acid is a potent antibacterial agent and can, in some cases, reduce the appearance of blemishes. 4