A Layered Framework for Biological Aesthetics: A Narrative Review of Regenerative Medicine in Cosmetic Science

Biological aesthetics applies regenerative substances, including platelet-rich fibrin, mesenchymal stem cells, and fat-derived biological matrices, with emerging adjunctive roles for peptides and exosomes. These approaches have gained attention because of their potential regenerative and biocompatible properties. However, comparative safety, clinical effectiveness, and durability remain uncertain because the available evidence is heterogeneous and, for several modalities, limited to preclinical studies or small clinical investigations. A layered approach addressing bone, fascia, fat, dermis, and epidermis is proposed as a framework for studying age-related changes across multiple tissue planes, but it has not been validated as a clinical treatment protocol. Challenges remain regarding regulatory clarity, product standardization, dosing, safety, and long-term clinical validation. This narrative review summarizes the biological basis, available clinical evidence, regulatory limitations, and research gaps associated with major regenerative agents and presents the multilayered model as a hypothesis-generating framework for future research.