A biomolecule naturally present in the dermis, hyaluronic acid is a hydrophilic sugar with remarkable humectant properties. It acts like a molecular sponge: it is able to retain up to 1,000 times its weight in water. In skin care, it prevents dehydration of the epidermis and the appearance of wrinkles. Plastic surgeons use it as an injection to fill in the signs of aging. Let's focus on one of the most effective anti-aging active ingredients.