Keratin hair smoothing treatment is defined as a chemical process where the hair is saturated in a formaldehyde solution, dried out and then straightened with a flat iron. Smoothing treatment for curly hair or slightly wavy hair introduces lost protein back into your strands to make it stronger and appear shinier. It is comparatively gentler and less permanent than hair straightening. The most popular hair treatment for smooth hair you might come across are Brazilian blowouts and keratin treatments. For the purpose of hair smoothening at home, we will focus on the easier and safer method to work with, the keratin treatment.