A sensible discussion & compilation of facts about the acid mantle, lipid barrier, retinoid production and more. See also this thread about avoiding chemicals & using cheaper, healthier, simpler, DIY treatments.  http://www.acne.org/messageboard/topic/313174-reducing-exposure-to-chemicals-recipes-alternatives-etc/   Your skin isn't dead leather & your sebum isn't dead grease. They are ecosystems for enzymes and other substances that play vital roles in skin function. Your s