It is very important to have the right shampoo for your hair and for this reason you have to know what is inside shampoo. There are many brands to choose from and some of them may not only not do their job properly but also harm your hair and scalp.
Surfactants are the cleaning ingredient in most shampoos. It is also used in other health care products such as body wash and tooth paste, as well as for more heavier tasks such as floor cleaning and even engine degreasing.
These are small molecules that attract water with one side and grease, oil and other dirt with the other. When you apply water and shampoo to your hair the surfactants attach to water and oil, pulling off all the grease and dirt and suspending it in water. When you wash the suspension off the dirt goes with it. Soap also has surfactants but you shouldn’t use soap on hair because it will take too much oils out of your hair and leave it dry and brittle.
Sodium Lauryl Sulfate (SLS) or sulfates in general (there are several of them) are the most common surfactant in shampoos. Although they do their job well they can be too harsh for drier, finer hair. They may cause irritation to scalp, leave hair more breakable and fade colour, but as they are not banned by health boards they are not dangerous for health.
There are also sulfate-free shampoos which are gentler to your hair and are supposed to make hair look healthier but some people find them less effective compared to sulfate-containing shampoos. Sulfate-free shampoos use organic products such as glucoside (which comes from plants such as sugar cane) and glycerin (which is comes from animal and vegetable oils) to clean. Sulfate-free shampoos tend to be runnier and not lather or bubble as much as the ones with sulfates. They tend to be expensive but are considered the better, healthier choice. Another concern with sulfates is it’s not a renewable source, petrolatum.
Some companies substitute Sodium Lauryl Sulfate (SLS) with Sodium Coco Sulfate which is made of the same stuff as SLS, coconuts but goes through a different purification process and is more organic, less chemically treated. None the less it should be avoided as it is almost as harsh as SLS. Some people prefer one over the other but Sodium Coco Sulfate is just a variation of SLS.
Shampoo also has conditioning ingredients that make hair cuticles smooth and make your hair shiny. Dimethicone and cyclomethicone are silicone oils that are supposed to make hair smooth and slippery. There are also humectant like panthenol that moisturizes and keeps scales on hair strands from sticking up.