Kojic acid is a depigmenting agent of fungal origin: it degrades melanin and carries out antioxidant activity which, by neutralizing oxygen, prevents the reactions necessary for the conversion of tyrosinase into melanin. It can be used alone or with other depigmenting agents such as mandelic acid or exfoliating substances. It is effectively applied in cases of keratosis, which are age spots on the face, hands, and forearms, that appear due to an alteration in melanin. If melanin production occurs irregularly and unevenly, light and dark areas (hyperpigmented spots) can be created, which, from an aesthetic point of view, represent a genuine problem