I have to use an anti-dandruffs shampoo six times a week, if I do not my hair is oily and then the dandruffs starts showing. I can go two times using another shampoo but for that I have to use an anti-dandruffs shampoo for at least one week and a half. You can forget three straight days without anti-dandruffs shampoo no matter how long I used one before. All that because when I was a teenager I tried a supposed natural shampoo for a few weeks!