Silk Peptide

About This Product

Silk peptide is produced by controlled partial hydrolysis of silk fibroin, stopping while the protein is still a chain of linked amino acids rather than separated into individual ones. It shares CAS number 96690-41-4 and the INCI name Hydrolyzed Silk with the fully hydrolysed grade, so molecular weight rather than nomenclature distinguishes them. That intermediate molecular weight, typically in the hundreds to low thousands of daltons, is the functional point. Chains long enough to interact with one another can deposit and entangle on a hair shaft or a skin surface, forming a continuous breathable film that smooths the cuticle, reduces friction and improves wet and dry combing, while still being short enough to remain freely water-soluble and to avoid the tackiness a full-length protein would give. Free amino acids cannot do this because they have no chain to entangle; intact fibroin cannot because it is insoluble. Silk peptide therefore occupies the useful middle, offering both a measure of substantivity and genuine moisture binding, which is why it is the most widely specified of the silk derivatives in leave-on products. It is used in hair conditioners and leave-in treatments, shampoos, skin care and serums, colour cosmetics and in film-forming and anti-ageing formulations. Bio Green Chem supplies silk peptide to specification on molecular weight range, nitrogen content, appearance, pH, solubility, ash and microbiology.