Ketoconazole can be used for treating the hairy part of the head or for more extent areas on the chest or in the face. Ketoconazole is absorbed into the body best when it is taken with a fatty meal or acidic drink like orange juice. Nizoral anti-dandruff shampoo helps to block the conversion of testosterone to dihydrotestosterone. Nizoral shampoo is unique because its effect is long lasting.