Skin-care professionals have a wide range of anti-aging products to choose from to help clients reduce wrinkles and other signs of age. Alpha hydroxy acids can be used to exfoliate skin, and antioxidants can repair damage done deep within skin by free radicals. Peptides can help skin produce collagen, and sunscreens can help clients prevent skin damage from the sun. But not every treatment works for every client, writes esthetician Kristina Valiani. "It will take trial and error to navigate through what an individual's skin responds to best."