Bioactive Agents for Hair Growth: Current and Emerging Therapies

Hair loss disorders, including androgenetic alopecia, alopecia areata, telogen effluvium, and scarring alopecia, affect millions worldwide and significantly impair quality of life. Although approved therapies such as minoxidil and finasteride remain the mainstay of treatment, their limitations have prompted the search for novel therapeutic approaches. This narrative review summarizes current evidence on bioactive agents used for hair growth promotion, including plant-derived compounds, marine-derived products, nutraceuticals, synthetic agents, peptides, exosomes, stem-cell products, and gene-based therapies. Literature published up to December 2025 was reviewed from PubMed, Scopus, Web of Science, Google Scholar, and ScienceDirect. Bioactive agents demonstrate antioxidant, anti-inflammatory, angiogenic, anti-androgenic, and regenerative effects through multiple molecular pathways involved in hair follicle biology. Emerging regenerative approaches have shown promising preclinical and early clinical outcomes, although large randomized clinical trials remain limited. Overall, bioactive agents represent a rapidly evolving field with considerable potential to improve the management of alopecia and other hair loss disorders.