I've been experiencing itching on my body and red ears, ringing in ears like too much histamine. I have taken methylfolate for a few weeks (400-800mcg), methylb12 (500mcg-1mg), with no side effects. I have also taken NAC alone before many times with no side effects. I started taking all 3 and experienced itching, so stopped everything for a few days. When itching subsided I took 400mcg methylfolate and 600mg NAC, itching returned. Is it the combination, or has this created a methyl trap in which I actually need more b12? I feel great mentally. Would I be fine if I took them several hours apart? NAC is recommended several times on the nutrahacker report. I have the CBS AG:1/2 mutation, but I've never noticed anything bad from taking MSM or NAC by itself.