Sorry, I meant to say he is taking 3 drops 3x/day - the maintenance dose. And he had his amalgams removed a long time ago, before he ever did DMPS. I will find out how long he took that dose, but it may have been shorter for him because he was not as toxic as many when he took it, having chelated over the years. He told me he thought I would need about six months. I can ask him how long he took it at the higher dose when I see him next, but it may be a little while (at least until I get the results of my tests).