I would recommend this as a reference source and buying it. It contains very useful information in many areas, such as endocrine problems and yeast etc. I have a few reservations. It only dedicates 5 lines to toxicity and detoxification, which more or less tell you to buy someone else's book. For one of the major contributary factors of Chronic Fatigue in many people, this is not really acceptable. If you are going to write a book about CFS, you can't just leave out key factors. My other reservations about the book are that it tends to mention many rather severe treatments and pharmaceutical drugs where these should only really be used as a last resort if at all, as many natural equivalents are just as effective. Lastly, the book doesn't clearly differentiate enough between what the reader should do by themselves, and what they should leave to a specialist to really prescribe the right treatment for them. It reads like a list of supplements. Apart from that, it is quite good.