Hi,
The best way to treat dandruff is to use a dandruff shampoo. Look for shampoos with ingredients such as zinc pyrithone, salicyclic acid, coal tar, selenium silfide, or ketoconazole. All of these ingredients have been shown to work on dandruff; to use the shampoo, apply it to your scalp and hair, rub vigorously, and allow it to sit for five minutes so that the ingredients can work before rinsing it out.