Health Improvement of Human Hair and Their Reshaping Using Recombinant Keratin K31

The study demonstrated that recombinant keratin K31, expressed in Escherichia coli and purified, significantly improved the properties of chemically damaged hair. When applied, K31 increased hair diameter by up to 49%, doubled the mechanical strength of bleached hair, and effectively straightened curly hair after a single one-hour treatment. The results indicated marked improvements in hair smoothness, diameter, and mechanical strength, suggesting that K31 could be a more efficient alternative to conventional keratins derived from wool or chicken feathers.