Hi there , i had faced a lot of problem with dandruff, so please see my observations below
there are two types of dandruff,
if you have a oily scalp and big flakes ys selsun blue will work,
the commonly seen ones are the dry scalp and white powder like dandruff , for this (which i had)
what i recommend is the Phyto range of anti dandruff products , they are natural , but effecitve as a long term therapy
i had the problem for many years and i found it quite effective, you need to be patient in using this as it will give results only in two weeks
there is two types of shampoos, and a lotion
the pharmacist can give you a good idea how to use them properly
the problem is it is not available in all pharmacies in Qatar , i saw it in lulu pharmacy and also in boots