How many times should I wash my hair if I have dandruff?

I would recommend that you do not wash your hair too often as this can risk drying out the scalp further, so perhaps 2-3 days on average.

As well as thinking about how often you wash your hair, to help manage this problem I suggest taking a look at what ingredients are in your shampoo. Any harsh chemicals are likely to dry out the scalp further so choosing a natural shampoo is a better option.

Other than this, aim to keep yourself hydrated by drinking lots of water. Eating sufficient good fats will also help to prevent your skin and scalp from becoming too dry.