First of all, you must make sure to choose the right shampoo for you. That is, one that is adapted to your scalp's characteristics and not to the condition of your lengths. We recommend washing your hair twice at a time: the first wash cleanses your hair and the second one allows the active ingredients to be absorbed into it. You do not need to use a large amount of shampoo even if you do not get it to lather, especially for the first wash. A walnut-sized quantity of product is enough for each use. There are also no rules about how often you should wash your hair, as we are all different in this matter. It is really up to personal choice, as long as you do not fall into the extremes.