I messed my scalp badly somehow, not even Nizoral would help anymore. Nizoral used to work perfectly in the past, was pretty much the only thing that did, no tea tree oil, tar or other stuff would help, maybe I become resistant to ketoconazole in Nizoral. I don't know.
Then I tried Kerastase Bain Gommage, it has salicylic acid (like in Rx stuff) and zinc pyrithione (like in Head&Shoulders, which alone is crap, imo, doesn't work) and it took 2 washes to normalize scalp, no more dandruff. And hair is incredibly shiny, other anti-dandruff shampoos leave hair dry. Kerastase is perfect, works beautifully and is lightyears better than anything else I've tried. Joico has nice scalp shampoo, but it took a couple week show effect and it wasn't as good for hair.