Efficacy of a Natural Complex of Polyphenols from Olive and Licorice Extracts in Improving Skin Complexion in Caucasian and Asian Subjects: Double-Blind, Randomized, Clinical Trial

Dysregulation of melanin synthesis contributes to the development of dark spots and uneven skin tone. Beyond being an aesthetic concern, this condition is frequently associated with psychological distress and a reduced quality of life across all ethnicities. This multicenter clinical trial evaluated the lightening efficacy of a natural complex of polyphenols from olive and licorice extracts in a multiethnic population (Caucasian and Asian). Efficacy was assessed through instrumental measurements, including spot pigmentation intensity, dark spot surface area, skin radiance, and advanced glycation end-products (AGEs), as well as dermatological evaluations (lightening effect and skin complexion evenness) and self-assessment questionnaires. The trial duration was 8 weeks and involved 66 subjects with dark spots, who were randomly assigned to either the active treatment group (SSG) or the placebo group (PLA). After 8 weeks of product use, the intensity of melanin staining within the dark spot and the surface area of dark spots in the SSG group decreased by 18.9% and 19.9%, respectively. Additionally, skin radiance increased by 21.2%. Instrumental variations were corroborated by the dermatologist clinical analysis and aligned with participant self-perception. Our findings clearly demonstrate the efficacy of the oral intake of a natural complex of polyphenols from olive and licorice extracts in improving skin complexion in Caucasian and Asian subjects.