From salons to the shelf, keratin is everywhere. But what exactly is keratin and what are the benefits for your hair? Keratin is a form of protein that makes up more than 80% of your hair. When you damage your hair through things like brushing, coloring and heat styling you lose essential keratin, making it rough and course. But Pantene’s Advanced+ Keratin Repair not only helps restores smoothness, but works to help prevent further damage at the keratin level.