Linda, I assume you have done some parasite cleanses just to rule out parasites(even though they are typically associated with allergic symptoms, and sometimes also with digestive problems)? Imo if you had no reaction to a 200 mg dose of ALA, then you probably do not have mercury poisoning now. Since you have been chelating for quite a while with DMSA, you should probably rule out lead toxicity or other heavy metal toxicity. I guess you have been taking many mineral supplements, the issue is whether your body is absorbing them properly(does you stomach make enough hydrochloric acid for proper mineral absorbtion? Perhaps you might have an endocrine problem or be deficient in some enzymes? Are you eating a good diet?