Positive the first time, which could have been metal removal or it could have been simply the stimulation of ALA. I do know that since then I have taken ALA on a one off basis, and no seeming "Metal Disturbance" so that may have not been the issue. As far as subsequent attempts I have noticed no real change either way. I would recommend with this one that you do test if you can, and read the literature thoroughly. You will have to be getting up at night to do true cutler chelation, so decide if that is worth it or not at this point for you.