Is glycolic acid best for chemical peels ?

Better peels exist: The type of chemical peel used, will depend on the patient's skin type and the skin condition he/she is trying to improve as well as depth of peeling recommended or desired. Nowadays peels are a combination of Alpha and beta hydroxy acids with added compounds like resorcinol, retinoic acid, etc to lighten, calm and hydrate the skin during recovery after the treatment.

It depends: Glycolics work fine if you only need a mild peel, or only have a limited amount of downtime. Tca peels can do more, but require a longer recovery. The hetter (croton oil) peel is, in my opinion, tremendously powerful and useful, but has the longest recovery.