<p>Fucoidan, a sulfated polysaccharide from brown seaweed, exhibits diverse biological activities such as anti-inflammatory, antiviral, anticoagulant, and anticancer effects. However, its structural attributes, influenced by seaweed species, environment, and extraction methods, pose challenges for standardization and industrial application. Issues such as composition variability, regulatory concerns, and high production costs further hinder commercialization. We aimed to provide an integrated analysis of fucoidan, spanning its structural characterization, biological activities, and challenges in industrial applications, while proposing strategies to enhance its utilization. In this review, we synthesized the literature on advanced extraction, purification, and bioavailability enhancement techniques to address key challenges in fucoidan research and industrialization. Critical factors influencing fucoidan’s structure and bioactivity were identified. Advanced methods improved extraction yields and reduced contaminants, addressing industrial barriers. This review offers valuable insights into the current state of fucoidan research and its prospects in the functional materials of dietary supplements, pharmaceuticals, nutraceuticals, and cosmetics.</p> Graphical abstract <p></p>