Shampoo's primary function is to remove grease and dirt from your scalp and hair. It is mainly water and detergent, but contains other ingredients to make it more appealing to use. Those other ingredients make shampoo thick, smell good and condition your hair. The ingredient ratio changes depending on the type of shampoo. For example, baby shampoo has a milder detergent than one designed for oily hair. There are shampoos for every age and hair type, and even for pets.
Surfactants, an acronym for surface active agents, are detergents. They are the most important ingredient in any shampoo because the foam they create lifts and removes dirt and oils. Complementary surfactants are often used. One creates more lather than the other. The secondary one, which foams less, counteracts dryness and helps reduce irritants created by the first. They are the sulfates and betaines or sulfosuccinates in the ingredient list on your shampoo bottle.
The viscosity of a liquid refers to how thick or runny it is. Salts and gums, such as guar or xanthan gum, are added to shampoos to thicken them. They also form a suspension to hold the shampoo's color and dandruff fighters. Gums are not as harsh to hair as salts can be because they are not absorbed by skin, but stay on the scalp surface.
Fragrances and Colors
Neither fragrances nor colors are necessary for a shampoo to clean your hair well. However, marketers promote shampoo based on its color, texture and smell to build brand loyalty. That's when you buy the same shampoo over and over again because you like the way it smells and feels in your hands and hair. If the shampoo you use has a pearly, gleaming sheen to it, that shampoo contains an opacifier. Opacifiers create a translucent effect when added to shampoos.
Detergents will leave your hair clean and oil free, but will not soften it. In order for your hair to be frizz-free and shiny, your shampoo needs a very mild acid to close each strand of hair's cuticles. These acids, better known as conditioners, are fatty agents that make your hair not only shinier but also easier to comb after washing. In your shampoo's ingredient list, conditioners are citric acid, dimethicone and quaternary agents.
All of the above ingredients are present in commercial shampoos, but in varying amounts according to their use. Shampoos for children and people with sensitive skin contain little or no fragrance, and do not foam very much. Shampoo for specific uses such as combating dandruff or maintaining hair dye color contain specialized ingredients, such as zinc pyrithione or color pigments. Most commercial shampoos also include preservatives to extend shelf life once opened. If you wish to, you can buy organic, preservative-free shampoo.