I didn't know mtx did that. Ctx often changes hair by making it curly, since it alters the DNA. Mtx is chemo, too.
Ever since I was on ctx 3 yrs ago, my hair "bends" closer to the root. I don't have much, of course, but it doesn't stand up straight like it used to. It used to be pretty curly, but the curl started a few inches out from the root.