Do not use head and shoulders full stop!! Dandruff, Hair extensions or not, it's utter ****, any professional will tell you that!! I have a client that wouldn't listen to my advice, her scalp was awful, but she insisted on still using H & S as she had dandruff DOH!!!! All that shampoo does us repeatedly strip the skin from your scalp, therefore it will never cure the problem, just cause it. She had a Brazilian Blo Dry with me, I gave her Nexus shampoo and conditioner to go with it, within days scalp had cleared up, for the first time ever, even the dry skin in her eyebrows! Nexus is great for hair extensions as I used it with mine. As long ad you use top quality shampoo and conditioner, maybe rub some moroccan oil into your scalp, only on top and hairline away from bonds, also on your extensions, can't see you'll have a problem.