The active ingredient of Ketoconazole 2%For fungal skin infections on the scalp which causes dandruff.DosageHow often you will need to use Nizoral will depend on the type of infection and on whether you wish to cure or prevent it. o Scales on the scalp (dandruff) and reddish brown patches with yellow or white scaling in the face or on the chest (seborrheic dermatitis): For treatment? twice a week for 2 to 4 weeks. To prevent relapses? once a week or once every 2 weeks. o Small? brown or white-colored? irregular patches on the trunk (pityriasis versicolor): For treatment? once a day for 5 days. To prevent relapses: each year? before summer? once a day for 3 consecutive days.Health WarningsDo not use Nizoral Shampoo if you know you are hypersensitive (allergic) to it. Symptoms of hypersensitivity include itching and red skin? occurring after application. As with other shampoos? avoid contact with the eyes. If this happens? however? rinse the eyes with water. • Always carefully read the full patient information leaflet.