I don't wash my hair with commercial shampoo, haven't done for years. It's fine, better than it has ever been in fact, silky, shiny, intensely dark and no more frizz.
I make my own shampoo with things like herbs, clay, soapnuts, apple cider vinegar, aloe vera, and add a few essential oils or hydrosols for scent - smells divine someone recently said. There's various methods for going no-poo, it's worth the effort of finding the right one for your hair.
My hair has balanced now and is happy to go indefinitely just getting washed with water and brushed without getting greasy or manky - but I like it to smell of something lovely sometimes. It needs to be well brushed with a boar-bristle brush and I use a wooden wide tooth comb to pull the tangles out.
There is an adjustment period which can last weeks - months, but using alternative hair-cleaning methods can really ease the pain of the changeover. And it is so worth it in the end.