Many people have been using the same type of shampoo for years. This is a mistake because the hair gets used to the formula, which means that it does not get affected with it over time. For this reason it is useful to change the type of shampoo from time to time. This is indicated by 3 clear signs. Among the most prominent of these signs is itching of the scalp and its secretion of excessive amount of oils. This may be an indication that the shampoo is no longer performing properly. Also, the hair becomes dull and light. But before that we must pay attention to the absence of other reasons such as changing seasons and the body’s suffering from deficiency in some food ingredients, especially magnesium. The shampoo should also be changed in case the hair strands are dry and broken, despite caring for it. This is one of the strongest indications that he no longer performs his job. In this case it is necessary to replace it with a product that contains a moisturizing formula and components such as shea butter or coconut oil.