I felt particularly good chelating early on with DMSA back at a time when logic would hold that methionine synthase was very underfunctioning based simply on the massive burden of mercury I have chelated since this time and the prior evidence of macrocytic anemia. I think DMSA has the potential to cause some symptomatic relief by inhibiting BHMT, the parallel pathway for generating methionine from homocysteine. Rich has cautioned against "overstimulating" the BHMT pathway at the expense of MS for years. I found his advice to be sound as TMG, in particular, was problematic. I would be curious if you also have trouble with zinc, a co-factor in the BHMT reaction. I don't think Rich has ever proposed this, but I think someone could use DMSA (every 3-4 hours please) to shift the flow towards methionine synthase because DMSA can effectively inhibit this reaction. I'm not sure how desirable this is, but it is interesting that the DMSA seems to help the excitoxicity. As I recall, the tissue expression for MS is vastly different than BHMT with MS having significant brain tissue expression vs. BHMT predominantly in the kidney/liver. (Rich please correct me if this is wrong) So, I could see how DMSA could provide relief to someone irrespective of metal burden.