Nizoral Ketoconazole Anti-Dandruff Treatment Shampoo treats dandruff and its symptoms such as dry, flaky, red, itchy scalp. This anti-dandruff and seborrheic dermatitis shampoo is dermatologically tested. It works by treating the underlying cause of dandruff, by restoring your scalp back to its normal healthy state. Nizoral shampoo contains ketoconazole, an antifungal medicine clinically proven to control dandruff. Nizoral shampoo is also indicated for pityriasis Versicolor.