Wet your hair thoroughly with water. Apply a small amount of Isdin Nutradeica Anti Dry Dandruff Shampoo to your scalp and massage gently with your fingertips, working it into a rich lather. Leave the shampoo on your scalp for 2-3 minutes to allow the active ingredients to work on the dandruff and relieve the itching and flaking associated with dry dandruff. Rinse your hair thoroughly with water, making sure to remove all traces of the shampoo. Repeat the process if necessary, depending on the severity of your dandruff.