Lactic 5% + Collagen Lactic 5% +collagen is a leave-on, self-neutralizing, mild peel. It is used once per week, after cleansing. Other products may be applied 20 minutes after use. Last Update: May 11, 2019 October 30, 2018 2338Technical DocumentsRelated Knowledge Base Posts -Pepti-ToneLED & Light TherapiesPepti-Acne