My wife has a cancer history, is it safe for her to take methatione?

Well I have a ADD problem. It takes me time to remember daily task some time. I took methatione for about 3 months it turned me in a robot. I was never late, I completed everytask, but I couldn't tell a joke to save my life. I helped me focus,but the price was to high for me so I just have learend to deal with my ADD. Good Luck