Alpha-hydroxy acid (AHA) is one of the most important ingredients to fight wrinkles and it was used as an ingredient in beauty products since ancient times as it can be found in different forms: glycolic acid, citric acid, lactic acid, tartaric acid, malic acid, and acid derivatives of the fruits. AHA is in fact an exfoliant that penetrates into your skin, dissolving the dead cells and allowing new ones to surface. The cosmetic products containing AHA purify pores, reduce fine lines, improve the condition of the epidermis and are therefore ideal for normal to dry skin because this acid exfoliates only the surface and does not penetrate too deeply, unlike BHA (beta-hydroxy acid). AHA in fact just melts in water while BHA is an oil-soluble ingredient. For this reason, BHA can penetrate pores that contain sebum and can exfoliate dead skin cells inside the follicle. We therefore recommend AHA products for people with sun-damaged skin and wrinkles, and BHA products for people with oily, acne-prone skin.