The most convenient way is to stir shampoo in a glass of water. Then, this “cocktail” should be allowed to settle. If there is white sediment on the bottom of the cup, this is a dangerous sign of poor quality, and you should avoid using such a product.
The quality of the shampoo can be judged by the level of surfactant substances. They wash the dirt well, but have a negative effect on the structure of the hair, destroying its protective surface, forcing the hair scales to “open” and making the hair brittle. In good shampoos, the surfactants are soft and synthesized from amino acids. In the low-quality product, the surfactants are either aggressive or used by manufacturers in small quantities. In addition, the composition of such a shampoo may include salt as a foam thickener. However, if the shampoo contains dimethicone, you can trust its quality – it is considered to be proven.
In general, the experts advise to remember this rule: the more detergent components the shampoo contains, the better. In this case, the concentration of each component will be miserable, and irritation of hair and skin will be smaller as well. Two detergent components on the package? Let this shampoo remain on the shelf. If it contains only sodium laureth sulfate and diethanolamides, while the rest of the components are just water and additives, the shampoo is guaranteed to be of poor quality.
