Nizoral is the only over the counter dandruff shampoo with Ketoconazole - a clinically proven, powerful dandruff fighting ingredient. Nizoral does more than just treat your dandruff symptoms - it works differently, getting right to the root cause of your dandruff by controlling the fungus that is causing it. Once the fungus is controlled, so are your dandruff symptoms. Ketoconazole, the antifungal active ingredient in Nizoral, is 10 times more effective at fighting fungus, the primary cause of dandruff, than the active ingredient in the leading dandruff shampoo. Clinical testing has shown that Nizoral relieves even stubborn dandruff among people who have suffered from dandruff for more than 10 years and have tried different anti-dandruff shampoos in the past. Clinical studies also shows that Nizoral is effective in controlling dandruff symptoms like flaking, scaling and itching in people with mild, moderate, and even severe dandruff. Nizoral is safe to use on color-treated, chemically processed and grey hair and its scent leaves your hair smelling good. Nizoral is so powerful that you only have to use it twice a week. Results from a published clinical study showed that ketoconazole, the active ingredient in Nizoral, starts working from the first use to start relieving dandruff symptoms and control the fungus that causes dandruff.