In the treatment of acne scar, the most commonly used peel is TCA (trichloroacetic acid). This peel, like most chemical peels, can be used at different concentrations, varying from 35% to 100% for acne scars. Lower concentrations are useful for atrophic box car scars and rolling scars while higher concentrations (eg 100% TCA Cross) can be used for ice pick scars which are more difficult to treat.
Salicylic acid and glycolic acid peels have been shown to be effective in reducing both inflammatory and non-inflammatory acne (active acne). These are useful for treatment of post-inflammatory hyperpigmentation (PIH) after acne as well. As PIH and acne scars are often found together, they are also commonly used when discussing the treatment of acne scars.
However, all procedures carry a certain degree of risks and so do chemical peels. This is why I strongly recommend doing them at a medical clinic with a doctor trained in performing chemical peels and who is able to best advise you on which peel, if at all, is most suitable for your acne condition. You should also consult your doctor regarding other treatments for acne scars, such as injectable PNs (Rejuran) and lasers. Hope this helps!
Dr. Joanna Chan