While keratin treatments are an efficient way to make frizzy hair more manageable, they do require a certain amount of maintenance. One big rule post-keratin is to wash your hair with sulfate-free shampoos. Not only is sodium laureth sulfate no good for keratin-treated hair, it can actual cause it to revert to its former state.
About Sulfates
Sodium laureth sulfate is an agent that helps shampoo to cleanse hair. However, if you lather up with shampoos that contain sulfates, the keratin will be stripped from your hair more quickly, and your results won't last as long. After a keratin treatment, stylists recommend opting for sulfate-free shampoos, which you can find at any beauty supply or drugstore.
Other Sodium
Sodium in shampoos isn't the only thing you should look out for. Some conditioners contain sodium. Check the labels on any products you purchase to ensure no forms of sodium are in your styling products. Salt water can reverse the effects of a keratin treatment as well, so if you want your hair to stay smooth for as long as possible, don't take a dip in the ocean.
What to Use
Keep your treatment up by using a shampoo and conditioner that are formulated for keratin-treated hair -- you can find these products at a beauty supply store. Products specific to keratin-treated hair not only help to maintain your style, but also to enhance and extend its life.
Other Things to Note
Swimming in a pool is off-limits as well since chlorine strips the hair of keratin too. For the first one to four days post-treatment you won't be able to shampoo your hair at all -- even with sodium-free shampoos. Exactly how long you wait largely depends on the type of keratin treatment you have. Discuss with your stylist for exact wait times.