One thing is for sure: after getting a Keratin treatment at the salon you should definitely use specialized keratin smooth shampoo afterwards to keep your hair sleek and shiny, otherwise the treatment will wash away with any other kind of shampoo. Using a high-end keratin shampoo helps you keep your hair as when you left the salon, not forever, but it will last longer.
Keratin is a protein naturally found in your hair, it protects it from external agents than can damage and kill its cells impeding them to grow normally. These keratin shampoos contain this protein, which helps hair stay protected, but it is not clear how it works by itself without the salon treatment first. It seems logical that applying the shampoo can foster a better growth making it stronger and sleeker because it is constantly receiving extra proteins, which should make that protective barrier stronger. But one could also think that an “overdose” of protein could also harm that barrier resulting in opposite effects.
Here is where the difficult decision comes; to use it or not to use it and based upon trial and error you will find what’s best for you. If after using keratin shampoos you notice your hair becomes weaker and less sleek you should definitely quit it as it may have sulfates, which are the main component in shampoos that are causing negative side-effects. If on the other hand, you witness a slight improvement in the look of your hair and you feel it is not weakening then you probably found a nice shampoo, which is helping you keep it healthy. Bottom line is any shampoo containing sulfates will ruin your hair so stay away from any shampoos that include them.
Another chemical you should be aware of is parabens. Although it is used in small amounts in some shampoos recent researches have shown negative side effects and if applied to hair it is in risk of becoming dry and frizzy due to its high molecular weight which demands a lot of water that is absorbed from your hair and scalp. Even though there is a lot of research to be done regarding parabens, it’s better to be safe than sorry.