Girls, could you please tell me who is saving themselves from dandruff…

Girls, could you please tell me who is saving themselves from dandruff? I used to be constantly bothered by any shampoo before, then three months ago I bought a new one, it perfectly suited me and there was no dandruff at all. It finished, so I bought a new one exactly the same and here the dandruff came back (( it's really visible, terribly uncomfortable because of this).