Dandruff caused by product build upi sn't technically dandruff at all, but rather a build up of products and other gunk on your scalp.
If you run your nails gently over your scalp and you pick up a while load of greasy white gunk, chances are you have product build up. We recommend using a good clarifying shampoo to give your hair and scalp a real deep clean, but be sure to use one with gentle ingredients (we'll help you find those). Some of the harsher ones can do you more harm than good. Don't worry, we will rate the shampoos on these ingredients, penalising those with any of the known harshers ones.Read more about Product Build Up.