Abstract
Hair cosmetics are undergoing a transition from conventional formulations based on passive surface deposition toward biotechnology-driven systems designed to interact with hair and scalp at the molecular level. Recent advances in proteins, peptides, biobased polymers, and responsive delivery platforms are enabling targeted repair of keratin damage, controlled reshaping, durable protection, and modulation of follicular activity. These technologies exploit biological specificity, renewable feedstocks, and programmable material properties to address limitations associated with traditional petrochemical ingredients. In this review, we examine how biotechnology is emerging as a unifying platform for hair cosmetic science, integrating biomolecular engineering, smart materials, computational design, and artificial intelligence to create more effective, sustainable, and biologically inspired hair-care solutions.