Thio vs. Hydroxide: Understanding Hair Chemical Reactions

Question
I want a permanent wave it has almost been a year since my last relaxer I want to get away from the hydroxide and go to thio which I understand is healthier for the hair. I just want to know your opinion....

Answer
You cannot mix thio and hydroxide. So, even though your last relaxer was a year ago, if it hasn't been cut off its still there. If you put a thio over that hydroxide, your hair will break where the two mix.  Chemicals of all types do not leave the hair even when a lot of time passes.  They must be cut off. Whether it 2 inches or 20 inches, it will break anywhere there is overlap.