Silk Sericin: From Silk Waste to High-Value Product

Silk sericin, a water-soluble globular protein traditionally discarded during silk processing, has recently emerged as a sustainable and bioactive ingredient for cosmeceutical applications. Rich in hydrophilic amino acids, it demonstrates moisturizing, antioxidant, anti-inflammatory, and wound-healing properties, making it well-suited for skin and hair care formulations. This review summarizes its origin, structure, and multifunctionality, emphasizing its potential as a natural and biodegradable alternative to synthetic cosmetic agents. Extraction techniques such as hot water, enzymatic, and advanced physical methods are discussed in relation to their influence on sericin’s bioactivity and applicability in skincare. The paper also highlights its role in promoting sustainability through zero-waste utilization of silk industry byproducts. Key challenges including scalability, stability, and regulatory compliance are considered alongside future opportunities in nanotechnology, protein engineering, and personalized skincare. Overall, sericin stands out among biomaterials for its unique combination of bioactivity, sustainability, and compatibility with cosmetic formulations, making it superior to many other natural and synthetic counterparts.