Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not credible

I first was excited about this book, but as I read more and more I realized how flawed the theories being proposed were. I cannot believe that this treatment will work at all. I have cycles even without using this treatment and also have gotten better by taking recommended supplements, exercise and sleep program giving in the book 'reversing fibromyalgia' by Joe M. Elrod. I feel this is a much more realistic book than this quack book about this guai medication...