Nizoral shampoo contains the broad-spectrum antifungal medication, ketoconazole 2% and is used to treat infections of the scalp by the fungus, Malassezia known to cause dandruff, seborrheic dermatitis, and tinea versicolor (pityriasis). There is also evidence suggesting that Nizoral shampoo may be effective in improving hair thickness and reducing hair loss.
Ketoconazole works by weakening the fungal cell wall membrane causing the cell contents to leak out thereby killing the fungus.
Nizoral shampoo is usually used twice weekly for up to four weeks with maintenance treatments every two to three weeks to prevent the condition returning. Nizoral shampoo should be used once daily for five days to treat tinea versicolor.