Chlorella-derived bioactives for cosmeceutical applications: functional properties, extraction strategies and translational challenges

Driven by the demand for sustainable cosmeceuticals the microalga, Chlorella, has emerged as a promising source of high-value bioactive metabolites. This review provides a critical and comprehensive assessment of Chlorella-derived bioactives, including proteins, polysaccharides, lipids and pigments, by establishing a bioactive-functional nexus that correlates these biochemical fractions with targeted dermatological pathways such as reactive oxygen species (ROS) quenching, tyrosinase inhibition and extracellular matrix remodeling. Integrating recent advances, this review identifies the key scientific and technological barriers limiting the industrial translation of Chlorella-derived bioactives. Advances in ultrasound-assisted extraction (UAE), natural deep eutectic solvent (NADES) extraction and supercritical CO2 extraction are critically assessed together with the major bottlenecks still faced, including lack of protocol standardization, inadequate bioactive characterization, limited industrial scalability and insufficient clinical validation. Our synthesis reveals that these limitations collectively create a persistent gap between laboratory-scale research and commercial implementation, despite significant progress in the development of extraction technologies. To bridge these gaps, we propose a strategic roadmap emphasizing integrated bioprocessing frameworks, the stabilization of thermolabile metabolites through advanced formulation innovation and the necessity for clinical dermatological validation. By shifting the research trajectory from empirical bench-top optimization toward scalable industrial logic, this work offers the technical foundation required to accelerate the industrial translation of Chlorella into high-performance, high-value and sustainable skincare solutions.