Hair keratin treatment is widely known for making hair smoother, shinier, and more manageable. It is especially popular among people who struggle with frizz, dryness, and unmanageable hair. But a common question many people ask is whether keratin treatment can actually repair damaged and dry hair. The answer is partly yes—but with some important limitations. Keratin treatment can significantly improve the appearance and feel of damaged hair, but it does not permanently “heal” hair in a biological sense.