My hair has never been dyed or chemically treated in any way. Heat has rarely been used, and always with protection against hair damage. I usually wear my hair down, but wearing it up in a bun or ponytail has resulted in some split ends. My hair is pretty thick (4.5” circumference in a ponytail) and straight, with a few natural waves. I eat healthily, exercise regularly, and have never smoked or drank. I am willing to sell at least 8”, but no more than 12”. Price is up for discussion.