I low-poo as needed with ION Color Defense Clarifying Shampoo (I don't have color-treated hair, but it's sulfate free, and I like it). I don't use a sulfate shampoo unless for some reason I've let someone put silicones or something else weird in my hair (which is seldom). I prefer just co-washing, but it seems I low-poo about once a week right now. Just gotta do what works for you!