The Glycolic Acid belongs to the Alphahydroxyacids. They are a family of acids in which the Citric Acid, the Lactic Acid, the Malic Acid and the Tartaric Acid all belong to. The Glycolic Acid has been known for very long time and it is quite interesting for cosmetic use. It has a better capacity to penetrate in the skin even if it has some collateral effects. The Glycolic Acid can be used in high concentration (from 50 to 70%) to take care of precise dermatological pathologies. The main mechanisms of Glycolic acid are: – reduction of the superficial layer of the skin; – thickening of the deepest layer; – stimulation of collagen and elastin’s production. Actions: 1 – moisturize, smooth down and give luminosity to the skin. A light desquamation of superficial layer of the skin will occur (the corneal layer). We stimulate the cellular turnover and prevent the aging. The young cells of the epidermis are clearly increased in the end of the treatment. 2 – collagen and elastin are stimulated and the action of Glycolic acid translates in an increase of turgidity and cutaneous thickness. Nowadays the Glycolic acid maintains an indication for acne. In fact it improves the local hygienic conditions of the skin, helping to normalize the sebaceous secretion and deeply cleaning the skin. It helps to sterilize the surface where the acne easily develops. For what concerns the cutaneous spots and aging, in my opinion now the glycolic acid is overcame by more efficient peelings that have minor collateral effects. It is suitable for domiciliary use, continuously applying low dosage lotion (for at least 3-4 months). Concluding, it is a good pre peeling: it is useful to prepare the skin for more effective actions.