Which penetrates deeper into the skin: Retinol or glycolic acid? Both are popular ingredients in skin care.

Hi Thanks for this wonderful question. Well the penetration of any peel is highly dependent on the concentration. 4% retinol is an active peel which is stronger. Not all patients are good candidates for 4% retinol peel. Your doctor will decide on that. Hope this will help. 

Thanks for your question.  Glycolic acid and retinol are both very different and affect the skin in different ways.  If you are talking about a peel, the depth will depend on the concentration of acid, type of peeling agent, and sometimes the time left on the skin. but you don't want to do something that penetrates completely to the dermis as your skin might heal poorly and with scarring.  As far as ingredients in skin care products, glycolic acid works nicely in some skin types for brightening and light exfoliation, and the retinoids aid in skin turnover, keeping pores open and smaller, and helping with acne-type lesions, fine lines, and sun damage.  So they each have a role when used properly.  I would consult with a board certified dermatologist who has had the most training in skin and skin care than any other type of physician, and they will help you sort out a great skin care regimen.  Best of luck!