If you live in the UK you can buy the 2% strength from Boots for about £5. You should use it twice a week (3 times at an absolute max if your hair can take it). If you want to increase the effectiveness, use T/Gel before shampooing with Nizoral as it aids absorbtion. On the days you arent using Nizoral use a good quality shampoo, and if you find Nizoral drying out your hair use a moisturising shampoo.