But that’s only the tip of what can cause dry hair—bleaching, overusing dry shampoo, heat styling, even the environment can leave strands dull and thirsty. And just like adding an eye cream ...

So when you suds up with a well-formulated dandruff shampoo, you're massaging in antifungal ingredients like pyrithione zinc, ketoconazole, and selenium sulfide to stop that fungus from ...